17" Triple Perc Scientific Glass Bong | Croia GlassThe Croia Glass 17 inch scientific glass bong is engineered for smokers who want maximum filtration, smoother hits, and a true high end laboratory style smoking experience. Built from premium borosilicate glass, this piece features a powerful triple stage tiered diffusion system that combines a base inline perc, a large rocket style tree perc, and a top secondary rocket perc. Together, these three filtration stages cool, refine, and condition smoke