Scientific Glass doesn’t come more scientific than the GRAV® Klein Sprocket Recycler. It features a sprocket disc perc that forces smoke and water through small slits to trap ash and tar for cleaner hits. And the filtration doesn’t stop there. The Klein Sprocket Recycler lives up to its name, moving smoke and water between two chambers so that it’s been thoroughly washed before it reaches you. Once the smoke and water separate in the top chamber, the water drains back into the bottom chamber and is then pulled back up in a continuous cycle until the hit is over. This process offers exceptionally smooth hits, and the clear glass allows you to watch a mesmerizing display.