Bike Quick Release Axle Skewer, Bicycle MTB Front &Rear Wheel Hub For Trainers QR 145/185mm 1 Pair Smooth cam action lever. Extruded CNC machined alloy nut. Quality quick release anodised alloy seat clamp skewer. Durable deep colour 5 micron finish in a wide colour range. Axle diameter: about 4.5mm. Front Skewer Size:145mm. Rear Skewer Size:185mm Material:Iron and aluminum alloy