This rearview radar with tail light pairs with your Edge bike computer or compatible smartphone to alert you of vehicles approaching from behind. Reliable rearview radar lets you ride like you know what's coming. One radar. Multiple display options. Pair it with your compatible Garmin device, your phone or both. The Varia app has you covered if you're using your phone as a primary or backup display. Shine brighter. Daylight visibility lets approaching vehicles see you from up to a mile away. It's small, it's easy to mount, and it works with just about any bike. Get more life out of your radar with up to 16 hours of battery life in day flash mode.