This is a light that can be charged via USB. It seems to be controlled by a dedicated app, but please check the manufacturer's website for details. The following is information from the manufacturer's website: Detailed Information Size: 45.5 x 44 x 20 mm Weight: 21g Light Source: Surface-emitting LED module Battery: Lithium-ion polymer 300mAh Runtime: High (30 lm): 1.5 hours Low (2 lm): 18 hours Flashing (50 lm): 45 hours Rapid (50 lm): 16 hours Group Ride (50 lm): 12 hours Daytime Hyper Flash (50 lm): 25 hours (Charging time: Approximately 2.5 hours) Estimated runtime when the kinetic function operates approximately 60 times per hour (when connected to SYNC KINETIC) High (30 lm): 1.4 hours Low (2 lm): 6 hours Flashing (50 lm): 7 hours Rapid (50 lm): 5 hours Group Ride (50 lm): 5 hours Daytime Hyper Flash (50 lm): 6 hours Water Resistance: IPX4 Mounting Band Diameter: Approximately φ26.0～32.0mm