The URSA Mini Pro B4 Mount from Blackmagic Design is a replacement mount for use on the URSA Mini Pro. This mount enables using your ENG-style B4 mounted HD lens on your URSA Mini Pro. The mount incorporates corrective optics that enable the use of a lens designed to work on a camera with three sensors and a prism, on the URSA Mini Pro, which is a single-sensor camera, without the image suffering from optical degradation.The lens mount accepts lenses with a B4 lens mount and features a locking lever to engage the mount's lock. The included shim kit enables precise flange distance adjustment when installing this mount on your camera.The integrated optics support HD resolution and are designed with spherical-aberration correction that compensate for the lens being used on a single-sensor camera while designed for a three-sensor/prism-block camera.