Whether you commute before the sun comes up or your evening training rides routinely keep you out past dusk, having some type of light is essential. NiteRider takes the standard red tail light one step further with its Sentinel 40 Tail Light, which combines a 40 Lumen tail light with a laser to keep you visible to motorists in the dark. When you switch the light to laser mode, the Sentinel projects lines onto the road, creating a virtual lane around you that alerts motorists to your presence and helps all road users coexist safely. To use it as a more standard tail light, choose from four other steady or flash modes. For the times you're riding with other people, use the Group Ride mode to stay visible without blinding or distracting the cyclists riding near you. The Sentinel 40 will only add about 73g to your frame, and you can easily recharge it on the go in any USB port.