KNOG Blinder Cog 1-LED Bicycle Tail Light - w/Red Light 1 LED generates 11 lumens for 500+ meters of visibility Target Run Time (hrs): 2 constant, 11 eco flash USB Charge Time: 2.5 hours USB designed to be exposed to the elements USB rechargeable, fully waterproof and wicked bright - 20 lumens front, 11 lumens rear Simple, tool free attachment in a compact package - only 15g Utilizes full-size on-board USB charger - no adapter or cable required