It most defintly will work with pendulum sights in fact I saw somewhere, before I got mine, that it works even better with pendulums. I am anxious to see how I shoot from my treestand this season. It is supposed to eliminate many problems there also.

I do know that it was a VERY WISE decision to install it on my bow.[&:]

The following paragraph is from the Timberline Archery website:
[ http://www.timberline-archery.com ]

The No-Peep will work with any type of sight; fixed pins, moveable sight, or pendulum. In fact, the No-Peep will enhance the accuracy of your pendulum sight. The reason most people shoot high from a treestand is a change in form rather than the effects of gravity. Most tend to drop their bow arm as they aim down. That shortens your draw length. The peep sight moves up as the string angle changes when the string moves forward. As little as 1/4” change in draw length can make you shoot 6”-12” high. A pendulum sight won’t correct for a change in form. This can’t happen with the No-Peep because it is attached to the bow, not the string. Your eye will be in the same position every time.