The Garmin GA 25MCX provides an amplified GPS signal for when you need more power. It comes with nine-and-a-half feet of cable and is also available in GA 25BNC, depending on which unit you have. Unlike the GA-27C, the GA 25 has an integrated magnetic mount only and no low-voltage mode, so it will put a greater drain on your batteries.
Works with StreetPilots 2720, 2620, 2610, c340, c330, c320, i5, i3, and i2; Nuvi 350, Quest, Quest 2; iQue M5, M4, M3, 3600 and 3200; GPSMAPs 76CS, 76C, 76S, 76, GPS 76 and 72; GPSMAPs 60CS, 60C, 60 and GPS 60; and GPS 12XL.