VITTORIA VA7R endcaps rear hub 142/12mm through axle (X12)

Vittoria 142/12mm hub end adapter cap VA7R (X12),  from qr hub to 12mm hub, push-in type, new design

The Vittoria hub adapter is an accessory that allows you to change the axle type (usually the front axle) of your bike, allowing for compatibility with different forks or to use wheels with different axle types. For example, you can switch from a 9mm QR (Quick Release) axle to a 15mm or 12mm thru-axle, or vice versa.