The shutter extension lever uses a lever action to trigger the camera shutter without pressing it directly. Pull the tail of the movable block and push the front end downward; the front end is designed to rebound, and the movable block drives the connecting block, sliding plate, and fixed pillar to touch the shutter. Why you need it - Enables reliable shutter triggering while diving, so you don’t have to press the camera shutter by hand underwater. - Keeps your hand and wrist steady underwater, reducing movement and improving shot consistency. - Ergonomic design ensures the trigger sits naturally on your finger and the elevation angle stays in place during underwater shoots. Compatibility - Suitable for DSLR cameras (models not specified). Practical use scenarios - Underwater macro photography while snorkeling or scuba diving. - Reef or wreck photography where easy, hands-free shutter control is beneficial. - Quick shutter access during drift or action shots without adjusting your grip on the housing. Key features - Shutter extension lever prevents the need to move your hand to press the shutter while diving. - Mechanism involves a movable block, connecting block, sliding plate, and fixed pillar to actuate the camera trigger. - Ergonomic, stable design that maintains the correct angle during underwater use.