Suitable for: for pigeons,cockatiels,parakeets,parrots,and other birds. Size:inner diameter approx 10mm/0.39inch,height 6mm/0.24inches wide application:widely use these leg bands to identify similar looking birds,use them to keep different breeds apart,identify your bird easily. material: aluminum material,extensible for long term use. Versatile Compatibility: Ideal for small parrots, canaries, budgies, and more, catering to the diverse needs of bird owners.