The 11" Gravitron is the smaller version of GRAV's flagship product, and it's still as fun and hard-hitting as it was in 2004. To use it, fill the outer base with 8" of water, place the bottle into the base, and load the 12 mm bowl. When you're ready to hit it, remove the bowl and inhale through the bottle's mouthpiece as you push it back down into the water. This will create a pressurized flow of smoke that will give you a massive hit in record time.