Shimano Metrea Dynamo Front Hub Produce 3 Watts You can easily power your lights by moving. The Shimano Metrea Dynamo Front Hub employs an internal unit construction that is lightweight and reduces drag while producing 3 watts. It is designed for 26" to 28" centerlock wheels and uses a 12x100mm E-Thru axle design. Features Internal unit construction that is lightweight and reduces drag while producing 3 watts Designed for 26" to 28" centerlock wheels Uses a 12x100mm E-Thru axle design SPECIFICATIONSHub Size12x100mm E-Thru Spoke Interface J-Bend Hub Drilling32HBrake Type Center Lock | Shimano | Metrea Dynamo Front Hub 12 X 100Mm Center-Lock | Black | 32H