@ dglock, That thing is hard as hell to get on and off, well a little easier to get on than off, which is great. It doesn't rotate, shift, slide or anything. There is a piece of rubber on the bottom of the grip that keeps it from sliding upward. this rubber "flap" grabs on to the bottom of the pistol and stops before the mag well, so no interference when loading or releasing the mag. It constricts on the pistol so no moving around. It stays exactly where you put it I LOVE IT! On an XDM I recommend putting the small backstrap on then the grip to compensate for the extra thickness and width. Feels so perfect. Let me know if you have anymore questions or want to see more pictures to help you decide. Take care.