Why Not? Percs are the glass features you see inside bongs that filter the smoke, ultimately cooling it down by the time it gets to your lungs. Percs are what make hits feels smoother than hitting a classic dry pipe, by forcing the smoke through water. There are several types of percs and each offers its own strengths. In this selection you will find everything - Honeycomb, Tree Perc, Showerhead, Turbine, Matrix, Sprinkler, Inline percs and many more!