If you like to go fast and need the most accurate speed logging GPS then this is the one for you! Bought this to track speed and routs of an iceboat but can be used for hiking, kiting, biking, running basically anything that you need a route and speed along that route. You have to ability to overlay coarse on google earth maps and see exactly where you were and how fast you went at any point along the way. Long life and nice features, this is a great GPS data logger. Have everything that was included in the original box. Price listed is the price, take it or leave it.From the manufacture: The Genie GT-31 is a wonderfully compact, business card sized navigator, carefully designed to embody ergonomic principles. It will comfortably fit in the palm of your hand, mount on the handlebar of bike or motorcycle, and can even be worn on your arm. The stylish unit can stand on your desk as a funky gadget, or, more usefully, can be placed on the dashboard in your car.The Genie GT-31 can run for up to 46 hours in power saving mode with the built-in lithium-ion polymer rechargeable battery. It can be recharged while connected to car cigarette lighter, mains power outlet, or your PC/Notebook.A state-of-the-art Thumb Stick allows for simple one-handed operation. This rugged navigator is waterproof to IPX7 standards, i.e. immersible in the water for 30 minutes at a depth of 1 meter, and, it floats!Genie GT-31 is not only developed to handle outdoor activities, but also to handle various professional uses, such as speed, hazard area, zone alerts, altitude, or other alerts defined by the user. To store trip data for longer journeys, there is a SD/MMC slot for extra data storage capacity. And, it can be used as a Real-Time GPS Receiver by connecting to your PC/Notebook. An optional Bluetooth version, named BGT-31 can be used with Bluetooth-enabled mobile phone or PDA phone.The Genie GT-31 is a fantastic, multi-functional GPS handheld device. Due to its flexible design, this device can be used as: - a GPS handheld navigator or - a GPS USB receiver or - a GPS Bluetooth receiver(BGT-31) or - a GPS data logger with dual storage (SD memory card + flash memory)