It's been categorically proven, by real white coated scientists, that you can't enjoy a ride unless you catalog every detail, which means the Garmin Edge 500 GPS is a fitness accessory as essential as your wheels, cranks, and brakes. It's a fully customizable bike computer that offers lots of data display options three screens with up to eight lines of data per so you can follow almost every detail of your ride, from temperature to cadence to gradient to speed, and then some. You can set them up in any configuration, so you can always find the info you're looking for. Garmin also designed the Edge 500 to be compatible with any ANT enabled power meter, too, so you can bask in your unsurpassed leg power when you're churning up a big hill or blowing away flat sections. The 500 uses GPS mapping, but it won't display a map or tell you which way to go. It will, however, track your map coordinates so you can see your ride after you're done. It' also compatible with the Garmin Training Center program a free download that'll help take your training tracking to the next level. The Edge 500 runs off a rechargeable battery that has up to 18 hours of life, and ships with two slim mounts for easy attachment to stems or handlebars.