The unique QuickShift Donut has been designed to be the most universal and flexible mount for common pole diameters as well as the easiest to install. The SD-DO features the “QuickShift″ lever which allows you to quickly move and lock the display freely along a pole without using any tools. The product readily adapts to poles 42mm and 50mm in diameter. The QuickShift Donut utilizes a ball joint that allows infinite and easy display adjustments for any viewing angle range up to 20 degrees in any direction. Even after the screen has been installed, it is easy to change its position from landscape to portrait and can then be securely locked into position. The inbuilt “Quick Release″ mechanism ensures hassle-free and secure removal or replacement of the display.