The Garmin Varia RVR315 Rearview Bike Radar is a simple and effective way to keep yourself safe while you ride. It pairs with your Garmin Edge unit or smartphone to alert you of oncoming vehicles that are out of your sightline. If you don’t have an edge, download the Varia App and you are good to go. The radar provides visual and audible alerts from up to 140 meters away. With a compact and sleek design, it is compatible with the seatpost of just about any road bike. With up to seven hours of battery life, you will worry less about charging and more about riding. The Garmin Varia RVR315 Rearview Bike Radar is a perfect way to increase your awareness and safety on your rides.