Ever run out of batteries unexpectedly? Annoying, isn't it? Now you can say goodbye to weekly battery changes with the Alltrolite® USB Rechargeable Carbon LED Bike Tail Light (FA2008)! The Alltrolite® USB Rechargeable Carbon LED Bike Tail Light (FA2008 is super bright, you can be seen easily from blocks away! It is SUPER BRIGHT, LIGHTWEIGHT, and STYLISH, GUARANTEE! All in one design bicycle light - Super bright 100 Lumens output bicycle rear light led - 180 degree visibility - No wires or external batteries - Only 26 grams total with internal battery - The Alltrolite® USB Rechargeable Carbon LED Bike Tail Light (FA2008) is Water resistant, weather tight design ensures all condition use - Can be used as a bicycle helmet light, mountain bike rear light, road bike lights, kid's bike safety light and More! USB Rechargeable - Charges from your computer or any device with a USB port. Smart Charging - 2 hour charging time - Automatic, fully charged cut-off system - Smart charging ensures longer battery life Simple control button - Conveniently located on top of the light for easy access 6 Lighting modes - Low/Mid/High/50% Flashing/100% Flashing/Strobe Mounting options - Horizontal or Vertical mounting Can Be Used as a Bicycle Helmet Light, Mountain Bike Rear Light, Road Bicycle Tail Lights, Kid's Bike Safety Light and More - Bicycle Rear Light - Bike Safety Light - Emergency Bike lights Rechargeable and Safety Bike Light .