PHOENIX STAR 21 Inches Freezable Coil Bong Triple Layer Showerhead& 8 Tree Perk PHX448 comes with triple layer showerhead and 8 tree perk for better diffusion and filtration for smoother hits. Phoenix Star percolator bong is 21 inches tall and constructed of 5mm thick glass for durability. This perc bong features glycerin coil which is connected with the base by a plastic kick clip. You can put the removable freezable glycerin coil in your freezer for one to two hours before starting smoke. The cooler and smoother smoke will not let you down. This freezable glycerin bong is also suitable for glass collectors.