Arkon's SPRM8RTE 2.5 inch Robust Octagon Ratchet Elbow features a 180-degree ratcheting joint. An octagonal button design on both ends of the elbow allow for connection to other octagon pattern components, including Arkon's Model SPRM8SKT Single Socket Arm with Octagon Button Socket. This highly versatile ratchet elbow measures 2.5 inches (64mm) tall.