This T-shaped perch is designed for use with HOEI holders with a 12mm diameter. The perching part is 15mm. It's a good option for those who have a holder and whose perches have been chewed. Size (approx.): 10.5cm x 6cm The holder and the bird are not included. It fits perfectly in my holder, but it may be loose in some holders. In that case, please wrap tape around the base. For a limited time, I'm offering a free 70g bag of hulled oats, which my parakeets and Java sparrows love, to those who want it. If you'd like it, please say "hulled oats please."