charging adopts a safe charging to get a better seal, safe to use underwater Fill light function: Full coverage and sealing , the light is up to 40meters fast charging, not need to remove the back case, 1 second to charging the light. (Fully charging in 2.5 hours Special hot shoe port, can be mounted on holder or 1/4 screw. for Camera cameras, other action cameras share the same mounting WIth 2500mAh battery for longer working time and high brightness.