【Minimal Assembly Required】Arrives 95% pre-assembled with clear instructions and assembly video guide. Backed by one-year warranty on motor, battery, and major components, plus lifetime technical support from Vivi. 【Vivi Powerful Battery & Motor】 – Equipped with a 48V/499Wh battery and a 500W motor (peak 750W), delivering a maximum torque of 75N.M. The battery supports fast charging (4-5 hours) for extended rides. Glide through your journey at up to 15.5 MPH, making every ride seamless - whether you're zipping through downtown or cruising along scenic trails. 【Five Working Modes for Various Usage Scenarios】 – Throttle Mode, Pedal Assist Mode ,Normal Bike Mode, Cruise Control Mode, 2 Km/h Walking Assist Mode. 【Enhanced Safety & Comfort】 – Premium features include mechanical disc braking system with parking function, seat tube shock absorption, plus a sturdy frame rated for 285LBS rider weight and 150LBS rear storage. 【Quality Certified】-SGS certified to UL2849/SGS certified to UL2271, our battery system meets the highest safety requirements for electric mobility devices. The IP65 waterproof rating ensures excellent protection against dust and water splashes, allowing you to ride confidently in various weather conditions.