Use a long lens, such as the M.Zuiko ED 12-100mm PRO, on your Olympus OM-D camera in its underwater housing with this 52mm Extension Ring from AOI. The ring fits OM-D mount housings and ports, and is specifically recommended for use with Olympus PT-EP08, PT-EP11, and PT-EP14 housings, and AOI DLP-07 and DLP-08 dome ports.