The string loop is what you use to pull the peep square to your eye. If the peep starts to roll one way or the other on you, just slide the knots of your string loop so that when you draw it will slightly twist the string and pull the peep square to your eye. As long as you keep the serving 1" off the peep, you shouldn't have any issues with ovaling.

What do you guys know about using the G5 with no string loop?

Ihadto train the string so the peep is in the right place. Training without the loop is a little harder since the loop can help rotate the peep into place if the loop is set-up to do so.

I have one too and love it so far. I do remember a post on this board or maybe another one talking about them losing their shape over time. So far I have not seen that. I'll see if I can locate that thread.

A string loop will help make a small correction on a peep's rotation, but it won't flip one around 90 degrees. You've got to adjust the peep so it comes back to your eye correctly with no help. It's a pain in the rear to do but well worth the effort. Then the loop will be a little insurance.

I've got a 1/4" G5 that I tried out on one of my bows. It worked fine, but I went to shooting barebow. I'm about ready to set up a bow with sights again, so it's coming out of retirement.

I could not get mine to work on my XT (no string loop). Got frustrated and went back to tubing. I had to twist my string and then the string would "catch" and then the G5 peep would stay, but I had to do it on every single shot in order for it to work and I always figured I would forget to twist the string before getting a shot at a deer.

you should not have to do that on every shot. once you get it in place so that it is rotating properly you may have to make a few minor adjustments but after that you should not have to touch it. The string loop is great for those minor adjustments

I have a 3/16 on my Drenalin and have had no issues.