KNOG Boomer Bicycle Head Light/Tail Light Set 1 Hi-Powered LED, 50 lumens output, Uses 2 AAA batteries (included) ?Front burn time of 4 hours constant, and 36 hours in flashing mode ?Rear burn time of 12 hours constant, and 72 hours in flashing mode 4 modes: Constant, Strobe flash, Fast flash, Random strobe 53 grams each (including batteries), 106 grams for the set