With Ikelite's underwater DLM 1.6" Flat Lens Port Extension, you can increase the length of their 5516.50 Flat Port in order to accommodate the Panasonic Leica DG Vario-Elmarit 12-60mm f/2.8-4 ASPH. POWER O.I.S. lens. Optional equipment may be necessary for lens compatibility. It's easy to remove the port from your underwater camera housing and attach the extension in its place. Once done, simply slide the port back on over the extension. See the DLM Type B Port Chart for the most complete, up-to-date compatibility information.