This is the latest tracker from Leadtek, a leader in GPS modules. This tracker unit integrates a SiRF4 GPS receiver, along with a GSM cellular module to enable live tracking of assets in a very small form factor. The antennas are internal to the unit, and an integrated Li-ion battery allows the tracker to remain active for 2-3 days between charges. The unit is extremely compact, at 1.6 x 1.6 x .5 inches, its one of the smallest self-contained trackers on the market. The tracker uses a free app available for Android, that allows a user to get live updates on their smartphone when the unit is moved, or on a on-demand basis. USB cable included for charging the unit. A SIM card and data/SMS plan is needed in order to use the unit (sold seperately).