The 16 gauge cz paved cartilage clicker is made from high polish grade 23 titanium (Ti 6Al-4V ELI ASTM F136). The smaller size has a 5/16" interior diameter with 1/4" long curved barbell. The larger size has a 3/8" interior diameter with 5/16" long curved barbell. The barbell is hinged on one side and snaps firmly shut on the other.