Large Black Aviator Harness for birds weighing between 600-1000 grams or 21 - 35 oz: Large macaws, triton cockatoos, small muluccan cockatoos * ESCAPE-PROOF! With other brands of harnesses, your bird can easily remove the leash and harness. The Aviator Harness keeps yourpet safe and secure. * Self-adjusting leash: Automatically adjusts from the chest to the back as the bird climbs and flies. Fewer pressure contact points on bird. * The strong steel slides have been powder-coated black to make them unattractive as toys. However, we have not heard of any bird yet that was able to break it. * Easiest to install - one piece design - No buckles or clips.