You'll always know what's coming up behind you. The Smart Rear Radar tracks vehicles approaching from up to 460 ft away, at speeds from 6-75 mph, and flags fast closing traffic directly on your Dynamo X display so you can ride more defensively on busy roads. Once installed, it runs quietly in the background, no daily setup, just added awareness every time you ride. Built to hold up in real conditions, it's designed to be installed once and left in place. *This accessory is a rider awareness aid only, not a replacement for shoulder checks, mirrors, or defensive riding.