As mentioned above, the Amod AGL3080 is powered by three AAA batteries and is a decent unit for geotagging purposes. Feature wise the unit is pretty basic, the unit constantly records your GPS coordinates into its 128MB memory which should last about a month, depending on the frequency of logging. The frequency of logging the coordinates can be set with the help of the accompanying software which is Windows only! Although the unit can be used with Macintosh machines, where it is detected as an external USB drive and shows all the GPS logs, there is no way to configure the device.