I have had my zero-effect on now for 2 years and it has not failed me. No problems with worry that it will fall off the shelf and I shoot carbons at 27" with a 115gr muzzy head as does my brother and we have no problems with grouping and the shots being where they are supposed to. Just ask the deer below hehe! MZE is the way to go.
Kill em' Wide and High!!!

Steven J. Collins (Trock63)
Bowdaddy Productions