Bicycle Lights Cycling Laser Tail Light, #1 Imports Water Resistant 2 Laser 5 LEDs 7 Modes Mountain Bike warning Back Rear Led Light Super high light LED. Red & Blue (Water Resistant) 2 laser launcher, 7 flashing modes, 260 wider visibility Suitable for the seat post : 20 -36mm Certification:CE & Rohs USE 2 x AAA battery(not included)