The Sea & Sea DX Compact Macro Port S II is a macro-type lens port for an underwater camera housing. It is compatible with RDX-series housings for Canon cameras, including the RDX-550D, RDX-500D and RDX-450D. Its threaded M67 port end allows you to mount the Close-UP Lens 125 (requires M67-M62 Step Down Ring). It also fits the Canon EF100 mm f/2.8L Macro IS USM lens. This port requires the NX Compact Macro Port Base. Depth rated to 330' (100 m), the port is constructed from corrosion-resistant anodized aluminum alloy and tempered multi-coated glass for protection against impact and the elements.