The RAM Cable Manager creates an integrated route for electrical wiring and cleanly covers installation holes. A great addition to any surface mounting application. The RAM Cable Manager is made of glass filled nylon which has the benefit of creating a barrier between the RAM Surface Mount and the attachment area; minimizing vibration while reducing fiberglass and gel-coat damage. This item will fit any of the 4″ diameter round plates with a 3 hole pattern. (Will not work with the AMPs hole pattern plates)