The Upline® Hammer Bubbler by Grav Labs is 5" tall and made on 38mm tubing. Its ladder perc restrictions create bubbler chambers that wash and filter smoke. Its fission downstem diffuses smoke through water and is fixed inside the bubbler to prevent damage. Two glass feet stabilize the bubbler between uses, and its carb and mouthpiece are ergonomically designed. No accessories are necessary for using this bubbler, and it works best with approximately 1" of water.
There is an Upline logo brandished on the front of every bubbler. Logo color is chosen at random.