The garmin varia radar tail light and radar display unit is the ultimate in rear light technology one of the new varia line of smart cycling devices from garmin this light is the first rear view radar system for bikes that warns of vehicles approaching from the rear up to 140 metres the light works wirelessly and connects with compatible garmin edge cycling computers edge 1000 edge 820 and edge 520 the edge computer or handlebar mounted varia head unit indicates when one or more vehicles