The RS-URSABC is a custom-fit rain cover for the Blackmagic URSA Broadcast camera. It's made from waterproof Nylon Taslan material and complemented by a soft Tricot interior layer that protects the camera and reduces noise during operation. The Taslan material is both waterproof (1000MM waterproof rating) and breathable (1000G/M² breathability rating), which provides protection from rain and dust while also allowing for heat from the camera to escape.
Clear Vinyl windows are used to provide unobstructed visibility of camera controls and the viewfinder. Velcro-sealed openings are carefully placed to provide full access to controls and power supply without allowing water to seep in. The adjustable lens gasket creates a tight seal around a wide range of lens sizes, including cinema lenses and matte boxes.  The waterproof material that forms the cover around the lens also adjusts to accomodate different lens lengths.
 
Watch this quick instructional video about putting on a Portabrace Rain Slicker on your camera.