These conversion kits fit our centre-lock straight-pull front hubs. Longer end cap goes in the disk side because the bearing is set deeper into the hub.
Please note that the 9mm thru-axle hubs are modified QR end caps so there may be cosmetic imperfections.
The 15mm option is a dummy product, necessary for our configurable wheels web pages to work. The axle of the centerlock straight-pull hubs is 15mm by default, then there are QR or 12mm caps which fit inside. So if you just remove the end caps from the axle, your wheel will be 15mm compatible.