Through machine learning, Lezyne's Ai Alert software filters for actual braking events, making it the most accurate and best cycling brake light on the market.Their Ai lights are an enclosed software system and do not collect rider data.Key Features:Advanced rear light with 'Ai Alert' brake sensing technologyDetects deceleration and changes output mode accordinglyMax Lumens: Max 400 lumens/80 hour runtime in Femto modeOutputs: 7 combined solid and flash output modes including a highly disruptive Daytime Flash modeBattery Capacity (mAh): 1900Recharge Type: USB-C rechargeable (cable not supplied)Weight: 71gFeatures: IPX7 waterproof standard, Wide Angle Optics 270deg of visibility, Aero and round seatpost compatible