1、3mm Standard Washer: Standard washer with a thickness of about 3mm, can support 9 to 12 speed flywheel after use. 2、Sturdy Material: Made of carbon fiber and aluminum alloy for rigidity and durability, reliable performance, durable. 3、Sealed Bearings and Closely Fitting: Sealed bearings protect the hub from dust and water. Closely fit the original machine hole position with accurate shape and size design. 4、Good Workmanship: Bicycle front rear disc brake hub can effectively improve the performance of your mountain bike. 5、Long Service Life: Fine workmanship makes the products durable, not easy to damage, and greatly extend the service life. Item Type: Bike Front Rear Disc Brake Hub Material: Aluminum Alloy, Carbon Fiber Color: As Pictures Shown Weight: Approx. 683g / 24.1oz Strip Hole: Front and Rear 32H Bearing: Front 2, Rear 4 Front Hub Specification: Quick Release: Approx. 100x9mm / 3.9x0.4in Barrel Shaft: Approx. 100x15mm / 3.9x0.6in Rear Hub Specification: Barrel Shaft: Approx. 135x12mm / 5.3x0.5in Barrel Shaft: Approx. 142x12mm / 5.6x0.5in Quick Release: Approx. 135x9mm / 5.3x0.4in 1 x Front Hub 1 x Rear Hub 1 x Washer 2 x Quick Release 4 x Quick Release End Cap 2 x Barrel Shaft End Cap