This thick glass piece features a double-wall glass design filled with glycerin. Glycerin is a nontoxic, gel-like fluid. Glycerin is used with these frozen bongs because it freezes much faster than water and stays frozen longer than water would! Manufactured from borosilicate glass. Designed in Canada Available Colours : Blue | Green Height: 10 Inches Thickness: 9mm Diameter: 3cm Shape: Beaker Joint Size: 14mm Weight: 675 g