SEE AND BE SEEN This rearview radar with tail light pairs with your EdgeA(R) 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(TM) 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. MAXIMUM AWARENESS Varia RTL515 rearview radar provides visual and audible alerts for vehicles approaching from behind up to 153 yards (140 meters) away. MULTIPLE PAIRING OPTIONS This radar works seamlessly with your Edge bike computer or compatible smartphone as well as select Garmin wearables or the optional radar display unit. WORKS WITH THE VARIA APP This smartphone app helps you increase your awareness by providing graphics - plus tone and vibration alerts - that indicate the position and speed of approaching cars. THIRD-PARTY APP COMPATIBLE When used with a compatible smartphone, Varia radar integrates with your favorite apps, such as Ride with GPS, to overlay your maps with rearview radar alerts. SUPERIOR VISIBILITY Alert motorists to your presence as soon as possible with daylight visibility up to 1 mile. COMPACT DESIGN Easily mount this sleek, compact device on the seatpost of almost any road-use bicycle. The vertical design allows for better leg clearance and a perfectly comfortable ride. PELOTON MODE Varia RTL515 features multiple modes, including peloton mode, which provides a low-intensity flash that is kind to other cyclists&&';; eyes when riding in a group. BATTERY LIFE Time spent charging is not as good as time spent riding. Get up to 16 hours of battery life in day flash mode and up to 6 hours in solid mode.