clamp on prisim side mount much shorter and angles causing only top part of clamp to make contact with helmet ...no matter how tight the 2 allen screws are prisim pulls off easily. possible solutions thicker rubber pads to conform to helmet which will also increase contact patch of sandwich clamp onto helmet.... funny thing no problem with the 10 or 20S.....

Sandwich clamp is longer providing stronger hold and angle of plate is flatter. contact patch area is just greater on these two units, not sure why the design change to shorter.

Thx

Jim