Red Laser Tail Light with Bike Lane Projection is the perfect way to let the road know who owns it: You. "How do I let the road know that?" You ask. In addition to flashing red lights, it also comes with two lasers that shoot to the ground and provide two guiding lines that serve as boundary indicators. To activate your Red Laser Tail Light, press the LED button atop the tail light to activate 1 of 7 light modes, from steady to 6 different forms of flashing. Press the LASER button atop the tail light to activate 1 of 2 laser functions: steady and flashing. 2 AAA batteries are included and replaceable.