Friction short ear. 360deg. rotation of nock after attached to arrow shaft. Less weight & bow string friction. Less than 3/16'' distance from arrow shaft to bow string, allowing decreased nock-to-shaft run-out. Designed to fit Easton's Super Uni-Bushing shafts. Big mouth, flared openings. Works w/Ultra-Nok, Ultra-Nok II Micro, rope nocking loops, Gator jaw release aids and finger shooters.