The Lezyne KTV Pro Alert Drive LED Rear Light is a compact, aero-post compatible rear LED rechargeable bike light featuring a Daytime Flash mode and our custom programmed “Alert” technology. It’s equipped with Lezyne\'s Wide Angle Optics lens that provides up to 270° of visibility and two high powered LEDs. When decelerating, the light will turn solid like a brake light and then provide a distinct flash pattern once stopped to alert riders or vehicles from behind. The cycle light will then change back to its previous output mode once the rider resumes his or her ride.Its co-moulded construction is super light, yet durable and has an IPX7 waterproof rating. The KTV Pro Alert Drive provides up to 75 lumens and has five output/flash modes. This KTV Pro features an integrated USB stick for convenient cable-free recharging and offers up to 14 hours of runtime.Lezyne KTV Pro Alert Drive LED Rear Light FeaturesCustom programmed Alert\" technology.Max. 75 lumens.Max. 14 hours runtime.Five Output modes.Integrated USB Stick.Waterproof.Lezyne KTV Pro Alert Drive LED Rear Light SpecificationsDaytime Flash mode.Custom programmed \"Alert\" technology.Wide Angle Optics.Co-moulded construction.Waterproof.Max. 75 lumens.Five Output modes.Integrated USB Stick.Max. 14 hours runtime.\"