1. Attach leash clip to one side ring.
2. Place harness right side down as pictured.
3. Put dog's front feet in large openings with center strap between feet.
4. Lift both rings of harness to center of dog's back and attach remaining ring in leash clip.
5. To release, remove one ring from leash clip.  Allow harness to drop and dog is able to walk away.

Initial sizing is achieved by measuring around the dog's chest, just behind the front legs.  Purchase this size.  Proper fit is achieved by putting the harness on the dog and adjusting the slides while the dog is standing.  The center ring should be on the dog's chest.  Rings should lie flat and just meet on the dog's back.  There should only be enough ease to allow two fingers between harness strap and dog.  (Much as the fit of a person's belt.)