This is the Sea & Sea Sea Arm SLR Set for Digital Underwater Housing Strobes Features: Adding Artificial Light to Underwater Photography and Video&';s is the Key to Better Images Having the Best Platform to Provide Lighting is As-Important as Artificial Light It&';s-Self Add Lighting Capabilities to SLR Camera Housing/Tray Complete Lighting Arm Set Compatibility: Compact Digital Cameras or SLR Systems Construction: Corrosion Resistant Anodized Aluminum Alloy with Rubber O-Ring Friction Gaskets, Stainless Steel and Brass Hardware System Weight: 16.1oz (456.43g) If you want to add lighting capabilities to your SLR Camera Housing Tray for better underwater photographs then you need a platform to mount a strobe or light. This Sea Arm SLR Set is what you are looking for.