The 7-1/8" white speaker back cover provides protection to the back side of the speakers, behind a bulkhead or wall. It covers wire connections and protects the speaker's cones. Slotted mounting holes match stud locations on most speakers. It covers wire connectors and the compact size fits PolyPlanar MA4054, MA4055, MA4056, MA8505, MA8506, MA6500, and MA5106 speakers. Sold as a single cover. The diameter size is 7-1/8".