If you haven't tried ripping with a glycerin coil yet, then all we can say is welcome to the dark side, my friend. A glycerin coil is essentially there to cool down the smoke before you inhale, but unlike other bongs, this uses a more hands-on approach. You place the glycerin coil in the freezer for a few hours and then into your bong to make sure the smoke is nice and smooth--it's much easier than filling up your bong with ice cubes or placing the whole thing in the freezer (which we don't recommend as it'll probably crack under pressure). The coil itself adds in another cooling step, as it increases the distance that the smoke must travel before hitting your mouth, giving it more time to cool off. There's nothing quite like ripping from one of these glycerin coil bongs, and if you haven't tried it yet, make sure it's on your bucket list!