Model number: BK7S. HITWAY BK7S electric bike. Size: BK7S: 1770mm 680mm 1100mm. Net: BK7S: 24.3kg. Battery: 36V 12Ah (BK7S battery removable). Gear: BK7S: 7-speed. The BK7S e-bike is equipped with double disc brakes at the front and rear.