New York Toner Xeccon Spiker1211 850 Lumen Bicycle Road Commuter & Racing LED Bike Light Super bright 850 Lumen, using 2nd generation Cree XM-L2 LED. Automatic Sensing mode senses surrounding light and adjust brightness accordingly. Fits 25.4mm - 40mm handlebar and helmet; helmet mount kit INCLUDED. Simple High/Low/Strobe mode, with strobe function to alert motorists. 5200mAh Samsung Li-ion battery provides enough power for up to 10 hours run time.