I use a peep that has 4 groves, but not spaced evenly apart. They are something like 11,1,5,7 o clock positions. I use WC string so the peep aligns correctly every time. It has been rock solid for almost 3 years. With the zebra string, I was chasing that thing all the time. If you don't get a no strech string, you'll be chasing your peep as well. Hope this helps.