Hope Pro 2 Evo Black Rear 12x142mm Conversion Kit Can also be used on Boost hubs to go from QR x 141mm to 12mm Thru Axle x 148mm Converts 135mm, 150mm, 170mm and 190mm QR hubs to 142mm, 157mm, 177mm and 197mm 12mm thru-axle hubs For Pro 2 EVO or Pro 4 hubs (only end caps are needed, no axle) Rear Hub Spacing: 177 Rear Hub Spacing: 197