The Browning® 5G NR (FR1) 600 MHz to 6,000 MHz Pretuned NMO Antenna has tuning by solid brass and low VSWR. Low VSWR (Voltage Standing Wave Ratio) provides a better impedance match to the transmission line, which provides higher power delivered to the antenna for better communication. This wideband antenna comes pretuned (no tuning required or needed) and is designed with premium materials to withstand all types of conditions. NMO mounting provides easy installation and secures the antenna into place. NMO mount is sold separately. .