When purchasing Jesses (or  making your own ), a good rule of thumb that many falconers follow is to  have them no longer than will allow the swivel  past the end of the tail feathers.
Remember not to let  your bird fly free in Bullet  or Mews Jesses. They can cause a bird to be snared on a tree branch or breach the gap between high voltage power lines
Our Bullet Jesses are made from High Grade Parachute Cord and Stainless Steel Bullets and Ball Bearing Swivels