HiSi is a Glass Bong Manufacturer that produces high end scientific bongs, dab rigs and ash catchers. HiSi features several unique percs that you wont find elsewhere such as U percs and Bell Percs, and base shapes like the hexagon bong.. Each HiSi bong has measurement lines for water levels and gives it an extra scientific look! These are some of the best high end bongs for your money, and you just found the best place to buy HiSi Bongs online!