This is a versatile four-way ratchet design for deck or side mounting with a quick-action handle for operation ease. It has a standard 1"-14 thread and a 9/32" hole for cable feed-through. Bolt holes: 5/16" dia., 3" x 1-1/2" on center. I also have an 8’ fiberglass antenna in a separate listing for $30 that will fit this mount. Search eBay “SMR Marine Electronics 8' fiberglass radio antenna” for the antenna.