Call it what you like, a bungie, a twister, a boing or a swing; the fact is that birds love the natural movement. The length and width of the coil are adjustable. Suggested for Finches, Canaries, Parakeets, Lovebirds and other similar size birds. The Spiral Bounces Up and Down and Swings From Side To Side, Birds Just Love It. For Budgies, Tiels, Etc.