[Special]Our Antenna +Your Handheld GPS = A Match 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 for Track and Train Handheld GPS for Alpha 100 200 200i Astro 220 320 430. []The antenna is to high temperature, cold and ice, and is not afraid of rain. Suitable for outdoor work. Connector: SMA-Male; Gain: 3.5dBi; VSWR:less than 1.5; Impedance: 50 ohm; Colour:Black&Orange Material:plastic Package Contents: 1 x Antenna Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.