Garmin's latest innovation lets us slice our cycling worries in half and then in half again. The Varia eRTL615 Rearview Radar Taillight gives us greater visibility on the road, lets us see and hear when vehicles are approaching from behind, and is powered by our e-Bike's battery so that we don't have to worry about charging the accessory up before hitting the road. The radar function pairs with the Varia app or our Garmin tech to alert us with visuals and sound to approaching traffic up to 150 yards away. The taillight features four modes, ranging from daylight visibility up to a mile away to a soft flash to alert fellow cyclists in your group without distracting or damaging their sight.