The ultimate rear cycle safety light with the best side visibility in its class. Now with a 150 lumen output.The Rapid X3 represents the pinnacle of safety light technology, designed to ensure you're seen both day and night. Doubling the brightness of CatEye's popular X2, the X3 puts out 300 lumens in the front and 150 lumens in the rear. Featuring CatEye's most versatile system, the Rapid X3 easily mounts to almost any application, including round and aero seatposts, seatstays, handlebars, forks and headtubes. With the optional Spacer X accessory, the Rapid X3 fits CatEye's FlexTightTM, rear rack, saddle rail and Fizik saddle brackets too. Add the best side visibility in its class, and you have the ultimate safety light.