The NiteRider® Solas™ 250 uses two powerful LEDs to produce an amazing 250 lumens of light output. It features 4 modes (2 flash / 2 steady) and is USB rechargeable. We’ve implemented what we call “Group Ride Mode” for cyclists who want to stay visible but not distract others in the pack.Key Features:Daylight Visible Flash (DVF),250 lumen super bright tail light,Group Ride Mode – be seen without distracting fellow cyclists,Easy on and off seat post strap mount with quick release tab,Convenient USB rechargeable,Super bright daytime flash mode,Be Seen by cars = Be Safe,FL1 Standard IP64, dust and water-resistantLumen Output: 250Run Time: 4:30 – 40:00hrsCharge Time: 4:00hrsWeight: 82gBattery: Li-PoIncludes:,LED Tail Light,Seat Post Mount,USB Charging Cable,