By connecting Ikelite's 5515.20 Zoom Sleeve to the zoom ring of your Panasonic 7-14mm LUMIX G Vario f/4.0 lens, you will enable zoom control when the lens is inside Ikelite's 5516.15 Underwater DLM Dome Port. Place the required clamp around the ring and slide the sleeve over the clamp. Make sure that the teeth at the edge of the sleeve mesh with the housing's zoom gear, in order to allow for smooth operation underwater.