Small Birds
Finches, Canaries, Parrotlets, Parakeets, Lovebirds, Budgies, Cockatiels, Small Conures, & similar sized birds No More Than 5/8" (1.6 cm or 16 mm)
Medium Birds
Conures, Lories, Senegals, Ring Necks, Caiques, Mini Macaws, Pionus, Quakers, Small Cockatoos, & similar sized birds 1/2" to 3/4" (1.3cm or 13 mm to 1.9cm or 19mm)
Large Birds
African Greys, Amazons, Macaws, Cockatoos, Toucans, Hyacinth, Alexandrine Parakeets, Congos, Eclectus, & similar sized birds 3/4" to 1-1/4" (1.9cm or 19mm to 2.5 cm or 25 mm - 3.1cm or 31mm)