With 250 lumens and seven modes, the NiteRider Sentinal 250 rear light will keep you seen and safe in a range of light conditions. It even has a day flash to keep you seen during daylight. As it is designed with highly visible laser lines that mark out the road, this rear light helps to guide ongoing traffic and creates a virtual lane around the rider, thereby increasing safety even further. Thanks to the robust lens cover and the overall reliable construction, this light can take a beating from the worst weather conditions, as well as heavy-handed bike riders. Being a USB recharge light, it contains up to 45 hours of run time on a full charge and includes a battery indicator too, so you should never get caught out. Daylight Visible Flash (DVF) Highly visible laser lanes All in one, Laser and taillight Convenient USB rechargeable Group Ride Mode – be seen without distracting fellow cyclists Easy on and off seat post strap mount with quick release tab FL1 Standard IP64, dust and water-resistant Included: LED Taillight w/ Laser Lanes, Seat Post Mount, USB Charging Cable