Glycerin is a non-toxic gel composed of fatty acids. It's completely organic and commonly found in moisturizers, soaps, and even foods! It freezes quicker and stay frozen longer than water, plus it doesn't expand and contract so there's no added pressure on the glass.
Glycerin coils are freezable bong parts that provide an alternative to the classic method of adding ice to the neck of your water bong.
While ice catchers in bongs are helpful, when ice melts it raises the water level in the base and proves detrimental to the bong's function. With glycerin coils your bong will perform flawlessly as the gel is trapped inside a secure chamber.