The Blackmagic URSA Viewfinder is designed specifically for use with the URSA and URSA mini digital film cameras. It features a high-resolution 1920 x 1080 color OLED display, precision glass optics, and an adjustable diopter to fine tune to your vision. It also has a built-in digital focus chart to help when focusing on your subjects. To boost the longevity of the OLED screen, the viewfinder uses a built-in sensor that only turns the screen on when your looking through it. It screws directly onto the top of your URSA camera and is adjustable, so it can be used with the left or the right eye