Don't know much about this one. But if it works with magnets and the shock of the shot to release it,like one I used to have, I would stay away from it. The one I had needed to be retuned as the weather got colder. In really cold weather I would be sitting on stand with my bow in its holder and the rest would fall down for no reason. The magnet would just lose its grip. I believe it was an NAP also. I got rid of it and now use a Ripcord.