The SEA & SEA FOCUS GEAR FOR CANON EF 100MM fits this Canon lens only. It can be used on this lens in the MDX-5D Mark III, MDX-7D, and MDX-PRO 5 D Mark II, MDX-PRO Mark III, and MDX-40 D housings from Sea & Sea. This lens is compatible with the 30105 DX Macro Port Base and 30110 DX Macro Port 50 II. Focus is adjustable via the focus knob on the housing.