Frosted Bees Knees Mini Concentrate BubblerGEAR Frosted Bees Knees Inline Perc Mini Concentrate Bubbler Superbly crafted from 5mm thick borosilicate glass, this mini percolator bubbler from GEAR stands a diminutive 10. 5cm in height. Don't let the size of this piece fool you, though, EDIT Heads this miniature beauty packs a real punch. The bubbler features an inline percolator inside the main chamber which breaks up the smoke, increasing the surface area. This rapidly cools the smoke and makes