Features Model Number: AE-007985-201 Dimensions: W 2.43 in; H 5.25 in; D 1.5 in IPX-7 waterproof standard, impact-resistant rubberized housing Weight: 5.35 oz, without batteries; 6.7 oz, with Li-Ion rechargeable battery; 7 oz, with alkaline AA batteries Dual-core processor for lightning-quick map redraws, when panning or zooming Fast USB 2.0 data transfer to internal memory or SD card in device Proprietary Kalman filter for enhanced GPS accuracy Detailed onboard base map with major highways and thoroughfares worldwide, plus secondary and connector roads in the US 3-axis electronic compass with included accelerometer performs when held in any position while in motion or standing still Sensitive barometric altimeter for reliably accurate altitude readings Uses 2 AA batteries (included) Optional Travel Power Kit with DeLorme-supplied rechargeable Li-Ion battery Super high-sensitivity 32-channel Cartesio chipset by STMicroelectronics for rapid signal acquisition and ConstantLock satellite retention, even in challenging GPS environments Acquisition Times: 5-6 seconds, hot start;