Medium Red Aviator Harness for birds weighing between 425-600 grams or 15 - 21 oz: average to large eclectuses; medium macaws (severe, red fronted), large amazon parrots (double yellow, yellow nape), umbrella cockatoos and average to large african greys * ESCAPE-PROOF! With other brands of harnesses, your bird can easily remove the leash and harness. The Aviator Harness keeps your pet 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.