Brunton Atlas GPS and WAAS Receiver. Precision 12-parallel channel GPS+WAAS Receiver. Accuracy down to 3 meters. Built in Patch antenna with optional port for connecting external GPS+WAAS FA-8 antenna. Built-in, detailed background map of continental US and Hawaii. Internal back-up memory. Dual easy/advanced operation modes. Multiple map zoom ranges, 0.05-4,000 miles. Easy point and map cursor navigation/route planning. Compatible with most computer mapping software. Expandable memory. High contrast backlit LCD display, 4 level grayscale. Display size: 1.7" x 2.2". Uses 2 AA batteries that provide up to 12 hours of continuos navigation time. Weighs 4.9 oz without batteries.