The Ultra-Nok II MICRO is lighter and smaller which will increase arrow speed and eliminate cable and overdraw interference. Is designed to be used with trimmed standard nocks, or Quality Archery Designs Tune-A-Nock F/S. Provides the ultimate, evenly balanced, release point directly behind the arrow. Stops arrow from falling off of the string, increases accuracy and consistency by improving arrow flight. Eliminates arrow pinching and bowstring wear. Unlike other metal nocking loops, the Ultra-Nok II MICRO has FOUR anti vibration screws, not just two, to keep it from sliding up or down the string. Will maintain positive peep hole alignment shot after shot.