The antenna has a mounting connector rather than a thread receptacle. This antenna mounts to a SO239 (CN-006) female connector, which fits a 5/8” diameter hole mirror or gutter bracket if required.
Tuning is by removing the set screw in the ferrule at the base of the antenna and cutting the whip to the required length with bolt cutters.
MODEL A – 212
4Ft (1219mm long) S/S G.I.D. Whip
VHF High Band 148-175 MHz
Ground Independent 2.5Db Gain
VSWR < 1.2 : 1
Impedance 50 Ohms