Years of research has determined that our Parrots will be healthier, more active and more confident when flighted. The harness has an elastic restraint so as not to do any harm when they reach the limits of the harness. The medium harness fits Parrots from 450 - 600 grams such as Eclectus, Medium Macaws (Severe, Red Fronted) Large Amazons (Double Yellow, Yellow Nape) Umbrella, Congo Grey. The one piece design makes it easy to put on and it comes with full instructions on a DVD. Add a Flight Line that is a tangle proof system allowing up to 250 feet of flight area. Also check out this great video from Good Bird, Inc. that offers some helpful tips on harness training your Parrot.