wear and maintains positive peep alignment. The multi-postion back plates adjusts to fit all arrow nocks. Other metal loops when twisted or accidentally bumped will cause arrow to dislodge from rest or pop off string but the Ultra Nok XL will not! Don't settle for less. To maintain accuracy shot after shot you need the four screws with nylon patches eliminating nock point creep that the Ultra Nok XL provides. It is extra long to allow more room for your release aid. Quality Archery Design Ultra Nock XL.