#1 LED Tail Light! Cycle Safe CS-4 BLINK, Safest on Amazon with a Lifetime Guarantee! Super Watt Flash for High Visibility! Bright for Maximum Exposure! Red Blinking Side Marker, or Blinkie Rear Light (Red) BRIGHT AND SAFE -- The whole point of lights is to see and be seen! With 2 individual ultra LED bulbs, the CS-4 delivers on being BRIGHT, letting everyone in the vicinity know that you're around. Whether you're riding at night, dusk or in broad daylight, the CS-4 will grab the attention of others on the road, keeping you safer. LONG BATTERY LIFE -- Nothing is worse than having lights that don't work. Three easy to replace (and included) AAA batteries get you hours upon hours of flashing time with the CS-4. Given the high efficiency of the LED's you won't be worrying about charging battery packs for your lights. The CS-4 just keeps going. SUPER FLASH -- Most bike tail lights flash. But typically they pulse methodically which can blend in with other lights at night. The Super Flash feature of the CS-4 shatters darkness with an intense flash amid its normal pulsing. With a brighter than normal flash every few seconds, you will grab the attention of everyone around you. BOLT-ON ATTACHMENT -- Whether you're heading out for a workout, commuting to the office, or spinning around town, spending time putting lights on your bike is not your objective. The CS-4 easily slips onto the bolted mount allowing you to quickly put it on or take it off. Once on, the solid mount holds the CS-4 in place without worrying about straps or positioning. Bolt on the mount once, and you will get years of use without the need to readjust the angle, placement and orientation. Simply snap the CS-4 on the mount before a ride and youre ready to go. LIFETIME GUARANTEE -- At Cycle Safe, we not only believe in our products, but we use them daily. On the road and trail, they illuminate our way and keep us safe. Our goal is that every cyclist would be as safe as possible. If you find that for any reason, our lights don't provide you the light and safety you need or are hoping for, we will send you a refund. It's a no questions asked policy, because we are convinced that you'll be completely satisfied with the function and quality of these lights; which is why we guarantee them for life.