This heavy-duty clear polycarbonate case is contoured to the camera, durable, and completely corrosion free. Unlike aluminum housings there is a clear view of the main o-ring seal, port o-ring seal, camera controls, and dry inside. Mechanical controls are The housing is fully functional to a depth rating of 200 feet (60m). The housing is only slightly negative in salt water depending on choice of lens port Controls are provided through the housing for every camera function except the multi-controller and kept water-tight with Ikelite pioneered Quad-Ring seal glands proven to be the most reliable method of sealing controls. A large zoom control knob can be comfortably reached without removing your hand from the handle. A full range of optical grade dome and flat ports accommodate most macro, wide angle and zoom lenses. The standard port line offers compact and affordable options without sacrificing image quality. The modular port system offers maximum versatility and performancewith interchangeable 8" dome and flat port assemblies. Port attachment is quick and easy with a simple locking system and the port o-ring seal is clearly viewed through the housing. Lens ports sold separately. The Super-Eye magnifier comes standard and offers enhanced visibility of the camera"s viewfinder while wearing a diving mask. The camera"s large LCD screen can be clearly viewed through the back of the housing. The live preview feature of the Canon 50D model is accessibl