1This is a highgain antenna of super quality, made of metal and durable. 2Expandable telescopic antenna is fit for garmin astro 320 430 900 / alpha 50 100 handheld GPS. 3The antenna receives a stable signal, which increases the range you can obtain. 4The installation method is simple and does not require complicated procedures. 5It comes with direct sma connectors for garmin astro and for alpha. It connects for astro/alpha through a standard sma direct connection connection.Item Type: High Gain AntennaMaterial: MentalApplicable model: Fit forGarmin antennaHandheld GPSFolded Size: Approx. 21.7cm/8.5inExtended Size: Approx. 127cm/50inVHF Frequency: 136-174mHzGain: 3.0dbiHow to Use:This antenna increases the range you get.Easily install the flexible antenna by hand comes with direct sma connectors for garmin astro and for alpha.It is a portable antenna for Garmin alpha 50 and for alpha100, for garmin astro 320, 220, 430 and for 900 handheld devices. 1 x HighGainAntenna