[UNIVERSAL BAR FITMENT] The adjustable antenna mounting bracket features a clamping range of 20mm to 45mm (0.79" - 1.77"), making it perfectly suitable for semi-truck mirror arms, roof racks, bull bars, and tubular rails. Features a standard 16mm (0.63") mounting hole. [NMO TO SO239 ADAPTER INCLUDED] Comes equipped with a high-quality NMO to UHF Female (SO-239) connector. Built with a brass base, gold-plated center pin, and a rubber O-ring for superior signal transmission and reliable weatherproofing. [HEAVY DUTY ALUMINUM] Constructed from premium, corrosion-resistant aluminum alloy with sturdy stainless steel bolts. This rugged walkie talkie antenna mount ensures strong stability and withstands harsh outdoor weather conditions during long drives. [NO-DRILL INSTALLATION] Easily install your mobile radio antenna without drilling holes in your vehicle. Simply clamp the bracket onto Mirror Arms/Bumpers/Roller Bars/Roof Racks and tighten the four hex bolts for a secure, anti-slip grip. [WIDE COMPATIBILITY] An ideal communication accessory for truck drivers, off-roading, and overlanding. Compatible with most CB radios, Ham transceivers, VHF/UHF scanners, and two-way walkie-talkies requiring an NMO/SO239 setup. Antenna Bracket