USGLOBALSAT BT821 Bluetooth MTK GPS with Car Charger US Global Sat Bluetooth wireless GPS with MTK chipset High performance Bluetooth GPS receiver WAAS/EGNOS enabled by default Incorporates the 32-channel MTK GPS chipset By combining the BT-821 with Bluetooth enabled devices such as Smartphones, PDA's or laptops and your favorite navigation software, you can create a sophisticated navigation system at a fraction of the cost of larger dedicated navigation units