Cable thru hull fittings are designed to let antenna and electronic wires pass through the hull without letting water in. These Seachoice fittings are self attaching and require no hardware. Each one accommodates up to 2 wires while still maintaining a watertight seal. Installation of fittings requires a 3/4 inch (1.9cm) hole and can only be used on boats with a hull thickness of 2 inches or less. Available in Black or White.