It's got your back while you ride ahead. It plugs directly into your compatible eBike. It detects cars approaching from behind and provides audible and visible alerts when paired with your compatible Garmin smartwatch, bike computer or even your smartphone with the Varia app. This radar also has a bright tail light to make you more visible to motorists, adding peace of mind to every ride. And since you don't have to charge it between rides, that's one less thing to worry about. ANT+ connectivity and Bluetooth Low Energy technology pair with select apps and devices. Varia eRTL615 has rearview radar that provides visual and audible alerts on your compatible device for vehicles approaching from behind up to 150 yards (140 meters) away. Integrates with your select Garmin wearables, Edge bike computers or the Varia app on your compatible smartphone to provide alerts. Alert motorists to your presence as soon as possible with daylight visibility up to 1 mile and a light-flash pattern that changes to alert the driver. 4 light modes, including peloton mode, which provides a low-intensity flash that is kind to other cyclists’ eyes when riding in a group. Cable Sold Separately.