With a rough side for trimming, and a smooth side to protect sensitive birdie feet, Safety perches can help keep nails and beaks in top condition. Large size measures 13 inches long and measures approximately 1-1/4 inch in diameter. Appropriate for large birds such as Cockatoos, macaws and and similar sized birds. Non-toxic and safe for your bird. No sanded surface to harm feet.Stimulates leg muscles and promotes healthy feet.