For disc brake with Center Lock mount, for 15 mm thru-axle, black 6 V / 3 W, 100 mm installation width, for 20"-29", efficiency 72% at 15 km/h, optionally convertible to 12 mm or quick-release axle with adapters (0.710.296/5 & 0.710.295/7), flange diameter 66 mm, bolt circle diameter 58 mm, 456 g Axle Thru-axle 15 mm Installation Front wheel Type Article Design Hub dynamo Brake mount Hub Disc - Center Lock Braking surface yes , no Installation width 100 mm Electrical power 6 V / 3 W Flange diameter 66 mm For wheel Standard Main color black Hub body material Aluminum Spoke hole count 32 hole Spoke hole diameter for 2.00 mm Spoke type J-Bend suitable wheel sizes 20 " , 24 " , 26 " , 27.5 " , 28 " , 29 "