Compatible with any B-size RAM® Mounts component; ball and socket technology allows for near-infinite adjustability. Consist of 1" B-size rubber ball attached to a zinc coated metal U-bolt base. Designed to sit at right angles to the mounting rail, the U-bolt base accommodates rails from 0.5" to 1.25" dia. Includes black over caps to be placed over the exposed ends of the U-bolt as well as a composite adapter that can narrow the rail to a min width of 0.5".