【Specification】Connector: SMA-Male; Gain: 3.5dBi; V.S.W.R:less than 1.5;Impedance: 50 ohm; Length: 38CM/15inch. | 【Special】Our Antenna +Your Handheld GPS = A Match Made in Heaven. This extended range antenna can help you track your hunting dog, even in heavily covered areas. | 【Boost signal】This antenna is made of high-quality materials, each one has been strictly tested by professional instruments, and has better signal, which can increase the communication reception distance of your Handheld GPS. | 【Compatible models】Compatible With Track and Train Handheld GPS Garmin Alpha 100 200 200i Astro 220 320 430. | 【Durable】The antenna is resistant to high temperature, cold and ice, and is not afraid of rain. Suitable for outdoor work.