-The Battery Side Door for Gopro 9 provide access to USB port while battery and SD card are safely covered by the door, without fearing the battery will fall out. -The Clip on Battery Cover offers charging type C port for charging Gopro 9, so you can use power bank together with it, perfect for continuous shooting especially for recording time lapse or video -The Battery Lid offers connection for Microphone Adapter to add external mic,perfect for motovlogger youtube vlogging -CNC Aluminum Alloy Materia -Lightweight, mini size, portable for vlog