The top-end eTrex model comes loaded with wireless unit-to-unit data transfer, a three-axis compass and barometric altimeter for even more versatility. Pre-loaded worldwide basemap supports Garmin custom maps and BirdsEye™ satellite imagery. Loading additional mapping software is easy using Micro SD cards. 2.2" 65K color TFT display with 176x220-pixel resolution. High-sensitivity, WAAS-enabled GPS receiver with HotFix™ ensures fast start-up times. Compatible with spine-mounted accessories. Use the USB interface for data transfer. Powered by two AA batteries (not included) for up to 20 hours. Includes: eTrex 30, case, topo 100K card, BirdsEye one-year subscription, belt clip and USB cable. Dimensions: 3.9"H x 2.1"W x 1.3"D. Weight: 5 oz. for GPS unity only.