The Medium 11 Gravitron is super easy to use. Start by filling the outer base with about 8 inches of water, which should hit just below the decal. Then place the glass bottle into the base, and load the included 12mm bowl with your dry herbs. Place the bowl in the mouthpiece of the bottle, and light your herbs while slowly pulling the bottle upwards at the same time. Gravity will cause the bowl to self-ignite as you continue pulling upwards and the inner bottle will fill with smoke. When you’re ready, remove the bowl and inhale through the mouthpiece of the bottle as you push it back down into the water. This will create a pressurized flow of smoke and offer huge hits in record time. Get yourself a gravity bong youll be proud to keep on display with the Grav 11 Gravitron! Compatible with Dry Herbs. Grav Medium Gravitron Gravity Bong. First Grav Labs Product Created. 12mm Glass Bowl Slide. Sturdy 3.5 inch Base Diameter. World’s First Glass Gravity Bong. Note: Gravitron decal color varies. The item “Gravity Bong Glass 11 Hookah Water Tobacco Pipe Smoking Hookah Gravity Ripper” is in sale since Tuesday, February 16, 2021. This item is in the category “Collectibles\Tobacciana\Hookahs”. The seller is “gardenstatethrift” and is located in Philadelphia, Pennsylvania. This item can be shipped to United States.