Marine-quality, corrosion-resistant materials. For whip antennas up to 8' long. 1"-14 threads (1-14UNS2A standard) accept antennas with 1"-diameter screw mount–VHF Marine, CB, and Loran-C. Ratchet mechanism with locking bar allows fold-down plus 210° fore-to-aft and 210° side-to-side adjustments. Deck-mounted models install with four 1/4" fasteners.