Mounts in a 3/8" hole. This connector was made for mounting to a chassis and doesn't work with our wall plates. See BNCF-F-MT or BNCF-F-MT-75 for connector to mount to a wall plate or BNCF-F-MTI-75 for an isolated (insulated to prevent continuity between barrel and plate) version. Works on any size of coax cable, but requires a soldering iron (EXC7060) to terminate. The plastic threads prevent continuity between the connector shield and the metal plate or box that this gets mounted to.