Features of the CatEye Sync Core Headlight Compact and lightweight High power rechargeable headlight (500lm) Excellent daytime visibility in daytime HyperConstant mode Superior side visibility Round beam pattern with OptiCube lens Technology Built-in fast recharging circuit Lithium-ion rechargeable battery USB Rechargeable (Micro-USB cable included) 5 Light modes charging time: 3-6 hrs Mode memory function Flex tight bracket Optional helmet mount, center fork bracket and out-front bracket 2 available Light source: High-intensity LED x 1 Runtime High: (500 lumens) - 2 hrs Runtime Middle: (150 lumens) - 9 hrs Runtime Low: (100 lumens) - 15 hrs Runtime Daytime HyperConstant: (500/100 lumens) - 18 hours Runtime Flashing (100 lumens): 130 hrs Battery: Li-ion rechargeable battery (3.6V-2,200mAh) Recharge time: Approx 3-6 hrs (3hrs fast recharge using 1A or Higher USB charging adaptor, or using USB3.0) Recharge/discharge number of times: About 300 times(until the rated capacity drops to 70%) Other: Built-in fast recharging circuit, Lighting mode memory function, Helmet mount/ Center fork bracket/ Out-front bracket 2 Dimension: 41.5 x 33.5 x 93.5 mm Weight: 94 grams (light unit and battery) Features of the CatEye Sync Kinetic Safety Light Built-in acceleration sensor for Kinetic mode (automatically turns on with 50 lumen brightness when bike deceleration is detected) Excellent daytime visibility in daytime HyperFlash mode Group ride mode eye-friendly to team riders behind Superior side visibility OptiCube lens Technology Lithium-ion polymer rechargeable battery USB Rechargeable (Micro-USB cable included) Low battery indicator 6 Modes charging time: 2.5h Mode memory function Battery auto save (mode automatically changes to flashing when the battery power gets low) Light source: Red LED X 5 Battery: Lithium polymer rechargeable battery Runtime High: (40 lumens) - 1.5 hrs Runtime Low: (5 lumens) - 15 hrs Runtime Flashing: (30 lumens) - 50 hrs Runtime Rapid: (50 lumens) - 20 hrs Runtime Group Ride: (40 lumens) - 15 hrs Runtime Daytime HyperFlash(50 lumens) - 30 hrs Runtime High (When Kinetic mode is enabled 60 times per hour): (40 lumens) - 1.4 hrs Runtime Low (When Kinetic mode is enabled 60 times per hour): (5 lumens) - 6 hrs Runtime Flashing (When Kinetic mode is enabled 60 times per hour): (30 lumens) - 7 hrs Runtime Rapid (When Kinetic mode is enabled 60 times per hour): (50 lumens) - 6 hrs Runtime Group Ride (When Kinetic mode is enabled 60 times per hour): (40 lumens) - 6 hrs Runtime Daytime HyperFlash (When Kinetic mode is enabled 60 times per hour): (50 lumens) - 7 hrs Recharge time: 2.5 hrs (USB recharge) Mount size: Rubber band mount (Fits 26 - 32 mm seatpost) Dimension: 74.5 x 26 x 28mm Weight: 43g (with battery) Compatible with the CatEyeSYNC app App is required to pair the lights Allows you to synchronize all SYNC lights One touch turns all lights on/off Synchronized lights connection status indicator Control with Smartphone app Pair the lights (up to seven lights) Customize light modes View remaining battery level Turn on/off the lights Turn on/off synchronization with other lights Find me function lets the light flashing by tapping the button on app Before you purchase, be sure to check to see if y