These shims are designed for use with Genus GoPro Cage when GoPro Hero 3 and 3+ in naked state with LCD and battery BacPak. They allow to camera to be held in place in cage when camera is used with these accessories.
Note:These shims are suit for GoPro Hero3/3+ with its external LCD screen / battery. What you have to do is mounting whole unit with the special designed shim.Back cover is designed for non-external LCD / Battery user. Thus back cover can’t be mounted after this set-up.