Compatible with GoPro Hero 3 2 1 Skeletonhousing caseBackdoor with holes to make greater soundrecording performanceEasy to install one second to getBackdoor openings,not just good soundeffects,but also can greatly enhance battery cooling function Waterproof Case Backdoor with Holes BackDoor for Gopro 3,3+,4 GP135 Product Description Key Features: Compatible with GoPro Hero 3 2 1 Skeletonhousing case Backdoor with holes to make greater soundrecording performance Package Includes: 1x clear backdoor cover with holes Brand No Brand SKU OT776EL00BEHSNAFAMZ-28016 Model GP135