This Fixed Antenna Base features a flange mount base with a recess which, when filled with silicone sealant, will form a watertight seal. Designed to allow antenna wire to feed directly through the base, eliminating the need for a separate cable grommet. Accepts any standard antenna with 1"-14 threads, but is ideal for TV, Loran, GPS, VHF antennas, and radar arches. Constructed of corrosion resistant investment cast 316 stainless steel. Installs with three 1/4” FH fasteners (not included).