These modular monitor cage rails will fit all the most popular monitor systems and allow you to mount NATO-compatible accessories such as handles, clamps, and articulating arms. Interchangeable Anti-Twist Locator Pin inserts allow you to use all the most popular monitors and quickly secure them with a single bolt--SmallHD, PortKeys, etc. Accessories can slide along the length of the monitor rail, and when it's time to pack up, disengage one of the spring-loaded pins at either end of the rail and slide your accessories off. Use these to quickly attach a monitor to your camera or to build out your custom Director's Monitor. 1/4"-20 mounting screws are included, as is a hex wrench for installing the monitor cage rail.