The lezyne laser rear light produces 40 lumens in solid mode and projects laser lines on the road either side of your bike the silicone rubber mounting strap is compatible with round and aero seatposts co mold body design makes this light waterproof and durable side visibility lens design to provide 180 degrees of visibility intelligent power indicator leds monitor battery power and charging status features 2 laser lanes modes 2 solid modes 5 flash modes and laser only mode