Anyone used one of these? Any pros/cons using this over a D-loop?
Thanks

Ultra-Nok II,Tune-A-Nok and Ultra-Nok XL
These reliable and sturdy nocks keep your arrows from falling off the string at full draw. The Ultra-Nok 2 is a real advantage for shooters who use a release aid. Ultra-Nok eliminates string wear and increases accuracy. Machined from lightweight aircraft aluminum. The Ultra-Nock XL has multi-position back plates that accommodate all arrow nocks, regardless of size.