From MB Wiki

The Garmin Edge Series is a cycling specific product line within the Garmin fitness GPS category. It is primarily a GPS unit, but taps into other sensors like wheel speed, cadence and a Barometric Altimeter for increased accuracy. It also supports courses functionality.

Like most Garmin product lines there are multiple versions. MotionBased recommends the Edge 305 for the most accurate data and expandability.

• Edge 205 - a GPS that is custom built to be your bike computer, but does not take advantage of the extra sensors that make your GPS data more accurate.
• Edge 305 - comes with a Barometric Altimeter. You purchase the unit with either Heart Rate Monitor, cadence sensor, or both.

The Edge products come with a stem mount (or handlebar if you prefer)

Troubleshooting

Clear User Data

1. Power down device
2. Press and hold the mode button
3. Power on device
4. Confirm user data should be erased by choosing Yes

Useful when experience mysterious errors on some devices. Sometimes the unit may have corrupt data on it.