Small 5/16" Tip - Canaries, Cockatiels, Parakeets, Finches And Other Softbill Birdsmedium 7/16" Tip - Conures African Greys, Quakers, Senegals Amazons And Other Hookbill Birds Large 5/8" Nozzle - Large Parrots, African Greys, Macaws, Cockatoos Etc (good For Dogs And Puppies Too)extend The Use Of Your Gb-32 Oz Bottles With Replacement Parts.quality Stainless Steel Nozzle Safe Rubber Stoppersthree Sizes For All 32 Oz Lixit Bottles.