GRAV Medium Gravitron – 9" Glass Gravity Bong, 14mm

The GRAV Medium Gravitron is the compact version of the original all-glass gravity bong — a 9" piece built on the same principle GRAV introduced in 2004. A borosilicate bottle lifts inside a water-filled glass base: raising it creates a vacuum that pulls air through the lit bowl, filling the bottle with smoke without you drawing at all, and lowering it delivers that smoke under pressure in one dense hit. The GRAV Medium Gravitron uses 5mm borosilicate throughout, a 14mm female joint — the most common size, so most bowls already fit — and ships with a 14mm GRAV Funnel Bowl.

⚡ At-a-Glance Decision Summary

• What it is: A 9" all-glass gravity bong — the smaller sibling of GRAV's best-selling Large Gravitron.
• Why choose it: The gravity-bong hit at a size and dose that suits one person or two, rather than a room.
• The differentiator: The 14mm joint. The Large Gravitron is 19mm, which is a rare and awkward size. The GRAV Medium Gravitron uses the most common joint in the category, so bowls you already own almost certainly fit.
• Closed system: Smoke stays trapped in the bottle until you take it. Nothing burns off into the room.
• Build: 5mm borosilicate for both bottle and base, with a platinum-cured silicone grommet at the contact point.
• Grip: A hefty flange around the neck for lifting cleanly one-handed.
• Included: A GRAV 14mm Funnel Bowl.
• Confidence signal: $79.99, matching GRAV exactly. 96 reviews on GRAV's own site, on a design in production since 2004.

Summary: The GRAV Medium Gravitron is a 9" all-glass gravity bong with a 14mm joint, 5mm walls, and a closed system that wastes no smoke.

🧠 Our Verdict

Buy the GRAV Medium Gravitron if the Large Gravitron looks like more than you need — same mechanism, same build quality, a manageable dose, and a 14mm joint that works with bowls you probably already own.

Quick Summary

The GRAV Medium Gravitron is a 9" all-glass gravity bong: a 5mm borosilicate bottle that lifts inside a water-filled glass base. Lighting the bowl while raising the bottle fills it with smoke, and lowering the bottle forces that smoke out under pressure in a single hit. The closed system means nothing is lost. A platinum-cured silicone grommet protects the bottle-to-base contact point and a flange at the neck aids lifting. The GRAV Medium Gravitron uses a 14mm female joint and includes a 14mm Funnel Bowl. Price: $79.99.

GRAV Medium Gravitron – The Gravity Bong at a Usable Size

GRAV made the world's first all-glass gravity bong in 2004 and named the company after it. The Large Gravitron is the one people photograph; the GRAV Medium Gravitron is the one that gets used. Same mechanism, same 5mm borosilicate, same closed system — scaled to a dose that suits an evening rather than an occasion.

The mechanism is worth understanding because gravity bongs work nothing like a normal pipe. A glass bottle sits inside a base of water. Pack the bowl at the neck, light it, and lift the bottle. The space the bottle vacates becomes a partial vacuum, and the only route for air to fill it is through the burning bowl — so the flower combusts and the bottle fills with smoke while you do nothing but lift. Pull the bowl out, put your mouth over the open neck, and push the bottle back down. The descending bottle pressurises the smoke and pushes all of it into you at once. There is no drawing involved at any stage. GRAV's full gravity range sits in our Gravity Bongs collection.

The practical reason to pick this one over the Large is the joint. The Large Gravitron uses a 19mm joint, which is the least common of the three standard sizes and means buying a dedicated bowl. The GRAV Medium Gravitron uses 14mm — the size most bowls, slides and accessories are made in. If you own a bong already, its bowl very likely fits this. GRAV put it plainly: the standardised 14mm joint is compatible with any 14mm male bowl.

The rest is the same engineering the Large gets. Bottle and base are both 5mm borosilicate, which is five times thicker than the original 2004 design. A platinum-cured silicone grommet sits where the two pieces meet, protecting the glass at the only point it touches itself. A hefty flange around the top of the neck gives a positive grip for lifting — which matters when your other hand is holding a lighter. The wider GRAV range is in our GRAV collection.

Summary: The GRAV Medium Gravitron delivers the full gravity-bong mechanism at a personal scale on a widely compatible 14mm joint.

⭐ Who This Product Is For / Not For

Ideal for:

• Anyone curious about gravity bongs. The GRAV Medium Gravitron is the sensible entry point — a real one, at a dose you can judge.
• Solo use or two people. GRAV size it for personal use or sharing with a friend or two, and that is accurate.
• People who already own 14mm bowls. Your existing slide almost certainly fits.
• Conserving flower. The closed system captures everything the bowl produces — nothing smoulders off into the room.
• Anyone who cannot pull hard. Gravity does the drawing entirely.
• Small spaces. 9" and two pieces, versus the Large Gravitron's full-size footprint.

Not recommended for:

• Groups and parties. A medium bottle serves one or two. The GRAV Large Gravitron is the room-sized version.
• Anyone wanting a gentle, measured hit. A gravity bong has essentially one setting. The GRAV Coil Showerhead Water Pipe is the smooth, controllable alternative.
• Concentrate. A gravity bong is a flower device with no banger fitting.
• 19mm accessory owners. That is the Large Gravitron's size, not this one.
• Quick or discreet sessions. Two hands, a base of water, and a bit of ceremony.
• Travel. Two pieces of thick glass plus water.

Summary: The GRAV Medium Gravitron suits solo and two-person flower sessions on 14mm hardware, and does not suit groups, concentrate or subtlety.

⚠️ Known Limitations

• The dose is fixed by the bottle. Your only controls are how much you pack and how far you lift.
• Two hands and a flat surface required. The GRAV Medium Gravitron is not a one-handed piece.
• Flower only. No banger fitting, no concentrate use.
• Lift too far and the hit is gone. If the bottle clears the waterline the seal breaks and the smoke escapes at once. Everyone does this once.
• Fill the base halfway, not more. The bottle displaces water as it lowers, and an over-filled base overflows.
• Glass meets glass. The silicone grommet exists to protect that contact point, but the GRAV Medium Gravitron still wants a stable surface and a careful hand.
• Clear only. Stocked here in clear borosilicate.

Summary: The GRAV Medium Gravitron gives one fixed dose, needs two hands and a half-filled base, and takes 14mm bowls only.

⚙️ Features & Benefits

• 14mm female joint: The most common joint size in the category, so most existing bowls fit. This is the single biggest practical advantage the GRAV Medium Gravitron has over the 19mm Large.
• Closed system: Smoke is captured in the bottle and held until you take it. Nothing is lost to the room, which makes this one of the most flower-efficient pieces GRAV produce.
• No draw required: Gravity fills the bottle. You supply a lighter and a lift.
• Pressurised delivery: Lowering the bottle forces the smoke out. The hit arrives without effort.
• 5mm borosilicate, bottle and base: Five times thicker than the original 2004 Gravitron. Substantial and built for repeated handling.
• Platinum-cured silicone grommet: Protects the glass at the only point the two pieces touch.
• Lifting flange: A raised ring at the top of the neck for a clean one-handed grip.
• 14mm Funnel Bowl included: Ready to pack out of the box, and swappable for any 14mm male bowl.
• Straight sides, no perc: No slots, arms or coils, which makes the GRAV Medium Gravitron unusually simple to clean.

Summary: A 14mm joint, a closed all-glass system, 5mm walls and a protective grommet define the GRAV Medium Gravitron.

📐 Structured Specs

Summary: The GRAV Medium Gravitron is a two-piece 9" 5mm borosilicate gravity bong with a 14mm female joint.

🔌 Compatibility & Requirements

Compatible with:

• Any 14mm male bowl. The included Funnel Bowl is the intended slide, and three alternatives are in stock: the GRAV Cup Bowl in 14mm at $9.99, the GRAV Octobowl with a built-in glass screen, and the GRAV 14mm Caldera Bowl with a raised rim.
• Dry flower, ground medium. Too fine and it pulls through the bowl during the lift.
• Plain water in the base, filled halfway. No ice, no additives.
• Isopropyl alcohol and coarse salt. Straight glass sides make the GRAV Medium Gravitron easy to clean. Dr. Dabber ISO Snaps handle the bowl.

NOT compatible with:

• 19mm bowls. That is the GRAV Large Gravitron's size. The two Gravitrons take different bowls and slides do not swap between them.
• 10mm bowls. Too small for this joint.
• Quartz bangers and concentrate. A gravity bong has no banger fitting. This is a flower device.
• Ash catchers, adapters and percolator attachments. The joint sits on the neck of a bottle that moves. Nothing hangs off it.
• Ice. The base holds the water the bottle displaces; there is no room and no pinch.
• Dishwashers and boiling water. Neither is safe, and heat will damage the silicone grommet.

Summary: The GRAV Medium Gravitron takes 14mm male bowls and dry flower only, and shares no accessories with the 19mm Large Gravitron.

🧼 How to Use & Troubleshooting

Using the GRAV Medium Gravitron. Gravity bongs are the one piece most people have never operated, so here is the full sequence:

1. Fill the base about halfway with water. Halfway, not more — the bottle displaces water as it lowers, and an over-filled base overflows.
2. Lower the bottle into the base so it sits down in the water.
3. Pack the 14mm Funnel Bowl and seat it in the joint at the neck of the bottle.
4. Light the bowl and lift the bottle at the same time. The rising bottle creates the vacuum that pulls air through the bowl. You do not draw on anything.
5. Stop before the bottle clears the water. Lift too far, the seal breaks, and the whole bottle of smoke escapes.
6. Remove the bowl, put your mouth over the open neck, and push the bottle back down. Inhale as you lower.

Cleaning: Empty the base, separate the bottle, and wash both with isopropyl alcohol and coarse salt. With no percolator and straight sides, everything is reachable — the GRAV Medium Gravitron is one of the easiest pieces in the range to get properly clean. Rinse the silicone grommet with warm water rather than solvent, and keep it away from heat.

Troubleshooting:

• Problem: the smoke vanished before I took the hit. Solution: the bottle was lifted clear of the waterline and the seal broke. Lift less far.
• Problem: the bowl will not stay lit. Solution: you are lifting too slowly. The vacuum is what pulls air through the bowl — lift and light together at a steady pace.
• Problem: water overflowed the base. Solution: over-filled. Halfway is the mark.
• Problem: flower pulled through into the bottle. Solution: ground too fine. Grind coarser, or use a screened bowl such as the GRAV Octobowl.
• Problem: the hit is more than I wanted. Solution: pack less and lift less far. A partly filled bottle is a perfectly normal way to use the GRAV Medium Gravitron.
• Problem: glass grinding against glass at the base. Solution: check the silicone grommet is seated. It exists to keep those surfaces apart.

For a broader walk-through of how to judge glass thickness and construction before buying, read our guide on how to select the best products from a premium smoke shop.

Summary: Fill the base halfway, lift and light together, stop before the bottle clears the water, and lower it to take the hit.

⚖️ Comparison Table

How to read this table. The first three are gravity bongs and the last two are conventional ones — different jobs, not competing products. Within the Gravitrons, the choice is size and joint: the GRAV Medium Gravitron is $20 cheaper, gives a dose suited to one or two people, and takes the common 14mm bowl, while the Large is bigger, louder and takes a 19mm bowl you will need to buy separately. For most people the Medium is the more practical of the two.

Summary: The GRAV Medium Gravitron is the practical Gravitron — smaller dose, lower price, and the standard 14mm joint.

💬 Common Questions & Answers

How does a gravity bong actually work?
Physics rather than lung power. A glass bottle sits in a base of water. Lifting the bottle leaves a partial vacuum behind it, and the only path for air to fill that space is through the lit bowl at the neck — so the flower burns and the bottle fills with smoke while you simply lift. Then you remove the bowl, put your mouth over the neck, and push the bottle back down. The descending bottle compresses the smoke and delivers it. With the GRAV Medium Gravitron you receive the hit rather than inhaling it.

What is the difference between the Medium and the Large Gravitron?
Size and joint. The GRAV Medium Gravitron is 9" with a 14mm joint at $79.99; the Large is bigger, at $99.99, with a 19mm joint. The 14mm difference is the practical one — 14mm is the most common joint size in the category, so most bowls already fit the Medium, while 19mm is uncommon and usually means buying a dedicated bowl. Slides do not swap between the two Gravitrons. Choose the Medium for personal use and the Large for groups.

Will my existing bowl fit?
If it is 14mm male, yes. GRAV describe the joint on the GRAV Medium Gravitron as a standardised 14mm that works with any 14mm male bowl, and that is the most widely produced size — most bongs sold use it. At Angies Boutique three 14mm bowls are in stock: the GRAV Cup Bowl at $9.99, the GRAV Octobowl at $11.99 with a built-in glass screen, and the GRAV 14mm Caldera Bowl at $14.99 with a raised rim.

Why is it more efficient than a normal bong?
Because it is a closed system. On a conventional bong the flower keeps smouldering between your pulls and that smoke drifts into the room — you paid for it and never inhaled it. The GRAV Medium Gravitron traps everything the bowl produces inside the bottle and holds it there until you are ready. Nothing escapes. That is why gravity bongs get noticeably more out of the same amount of flower than most other formats.

What is the one mistake people make?
Lifting the bottle too far. If the bottom of the bottle clears the waterline the seal breaks and the entire volume of smoke escapes at once. Lift steadily and stop while the bottle is still sitting in the water — that is the only real technique in operating the GRAV Medium Gravitron, and everybody gets it wrong exactly once. The second mistake is over-filling the base, which then overflows when the bottle comes back down.

Is this a good first gravity bong?
Yes, and it is the one to start with rather than the Large. The dose from a medium bottle is substantial but judgeable, the 14mm joint means you probably will not need to buy a bowl, and at $79.99 it is $20 less than the Large. GRAV size the GRAV Medium Gravitron for personal use or sharing with a friend or two, which is an honest description. If it turns out you want more, the Large Gravitron is the step up.

How hard is it to clean?
Easier than most of the GRAV range. There is no percolator, no downstem, no slots and no coil — just two pieces of straight-sided glass. Separate the bottle from the base, wash both with isopropyl alcohol and coarse salt, and everything is reachable with a cloth or cotton bud. Rinse the platinum-cured silicone grommet with warm water rather than solvent, and keep it away from heat, since that is the one part that wears.

Summary: The GRAV Medium Gravitron takes a 14mm bowl, works by vacuum and pressure, wastes no smoke, and cleans easily.

🛒 Complete Your Gravitron Setup

• A spare bowl: the GRAV Cup Bowl in 14mm at $9.99.
• Keep flower out of the water: the GRAV Octobowl, with a screen built into the glass — useful on a gravity bong, where the lift can pull fine material through.
• A bigger pack: the GRAV 14mm Caldera Bowl.
• Cleaning: Dr. Dabber ISO Snaps for the funnel bowl between washes.
• The bigger version: the GRAV Large Gravitron at $99.99 on a 19mm joint.
• Something smoother for every day: the GRAV Medium Round Base Bong.

Browse the wider ranges in Gravity Bongs and Bongs.

Summary: Pair the GRAV Medium Gravitron with a spare 14mm bowl and isopropyl cleaning supplies.

✅ Authentic & Ready to Ship

The GRAV Medium Gravitron sold here is authentic GRAV glass. Angies Boutique buys direct from GRAV as an authorized dealer, so every piece arrives as GRAV packed it, with the 14mm Funnel Bowl and the silicone grommet included.

Priced at $79.99 — the same price GRAV charge on their own site. In stock and ready to ship, or collect it the same day in person at 838 N Broadway, Los Angeles, CA 90012.

Summary: The GRAV Medium Gravitron is authentic, in stock at $79.99, and available for same-day pickup in Los Angeles.