Andoer 2 in 1 Skeleton Backdoors with Fixed Pin Block Waterproof Case Backdoor + Perforated Backdoor Case Cover for GoPro Hero3+/4 and for New Hero3 Waterproof Camera Housing Made of ABS plastic, portable and durable. Suitable for GoPro Hero 3/3+/4. 2 in 1, one is a waterproof case back door, the other is a perforated back cover. The skeleton backdoors are with fixed pin block, which can mount one camera in a fishing rod or a firearm to capture footage by using other accessoxres. These two back covers have rectangular foam-rubber cushion, which have shock-proof function.