Derived from natural cuttlefish, Living World Cuttlebone provides natural calcium and minerals that are essential to caged birds. The hard, natural surface keeps beaks trim and sharp. The package includes a cage holder for easy installation. For parakeets, finches, and canaries. Size: Small (12.5 cm/5 in). Other sizes available : 82172 Living World Cuttlebone, small, 12.5 cm/5 in, 2-pack 82174 Living World Cuttlebone, medium, 13.5 to 15 cm/5 to 6 in 82176 Living World Cuttlebone, large, 15 to 18 cm/6 to 7 in 82178 Living World Cuttlebone, large, 15 to 18 cm/6 to 7 in, 2-pack 82180 Living World Cuttlebone, 10 to 26 cm/4 to 10 in, bulk,