Zefal USB Rechargeable Light Set Combo Front light:2 LEDs (15 lumens) 3 modes (full power, half power and flashing) 4 (full)/8 (half)/12 (flash) hour run times Quick-release handlebar mount for use a flashlight Rear light:2 LED rear light (10 lumens) 2 modes (flashing or constant) 5 (full)/10 (flash) hour run time Requires 2 lithium ion USB rechargeable batteries USB cord included Water-resistant design