3dB center-fed 1/2 wave coaxial sleeve. Designed to reduce signal fading in rough seas. This is probably the most widely used antenna on Coast Guard Vessels. Brass and copper elements, Chrome-plated brass ferrule with standard 1"-14 thread, includes 15' RG-58 cable and a PL-259 connector. One section. Suggested mount: 4187 (ratchet mount).