Collinear phased 5/8 wave with two coaxial chokes to suppress cable radiation. 6dB gain. This professional quality antenna is a performance powerhouse. It’s extra strong – sturdy enough to be self-supporting, even in high winds and high speeds. Brass and copper elements, stainless steel ferrule with standard 1″-14 thread, 20′ RG-8/X low-loss cable plus a PL-259 connector. Two sections: base 75″, tip 39″. Suggested mount: use only 4187-HD ratchet mount for self-supporting applications, or use 452 mounting kit if an upper support bracket installation is preferred.