CYCLIFE Outdoor Cycling Bike USB 1-LED 4-Mode Intelligent Sensing Brake Tail Light w/ Laser - Red
2 sensing mode: Acceleration sensing mode: can sense slow down of bike and then tail light will auto on for 3s; Smart sensing mode: can auto judge daylight / night and shifting to related working mode; LED mode: steady full strobe fast strobe and flashing in turns; LD laser has two mode: steady flash; With function of auto sleep and smart on; Auto off if there is stillness for 3mins; Can install on top tube or other parts of bike; Suitable for 30~34mm tube.