ConPus? GPS Antenna BNC for Garmin GPSMAP 545 545S 550/550S 555/555S 520 520S 205 GP-AC86 Amplified (active) GPS antenna to enhance and improve GPS signal reception. Built-in magnets for mounting on car rooftops or other metallic surfaces. Gain=28dB,RHCP,Z=50R, Center Frequency 1575.42MHz3MHz Threaded holes for mounting on aircraft fuselage, boat surfaces or car/RV/SUV vehicle surfaces. Length: 3m