Grav Labs STAX Halo Perc Filter Module
This piece features a pierced halo perc and adds height to your STAX mix and match bong kit! From Grav Labs in Austin, Texas, the STAX Halo Perc Filter is made of 5mm-thick laboratory-grade borosilicate glass, with a 34mm ground joint at the top and bottom to fit in between STAX bases and mouthpieces, or stacked with more filters! The 34mm joint is grooved on the outside to perfectly hold the 34mm joint clip for a more secure connection.