URSA 4.6KTurret (Active EF Mount) sensor from Blackmagic Design is an upgradeable Sensor and Mount for Blackmagic URSA EF Digital Cinema Camera. This unit has the 4.6K sensor, as such it offers a higher performance image sensor. It has several best function, such as lens mount, sensor, as well as lens control connections. With the included four bolts, this device can be simply attached to your Cinema Camera.