Marine Fiberglass 1/4 Wave CB Antenna (210-0976) Installation Faxback Doc. # 31927 Routing and Connecting the Antenna Cable If routing the cable through the mounting surface, drill a hole 3/4 inch (2 cm) in diameter to accomodate the cable and connector. The rubber grommet is used to plug (weather seal) the hole after installation. NOTE: The hole may need to be enlarged slightly to allow the connector to pass through it. (IR-03/21/96)