The most advanced GPS in the eTrex range and especially noted for its option to add a micro SD memory card. The eTrex 30x also has 3-axis tilt-compensated electronic compass and a barometric altimeter. You can also wirelessly share waypoints, tracks and routes with other eTrex 30x devices and thereby quickly update them with data. If you have a Garmin Chirp wireless beacon (792065), eTrex 30x can track it, and receive data from it, when you approach it. Data might, for example, contain the coordinates for the next waypoint.