Many components are specific to the XC or the Enduro hubs so choose carefully. Rear axles fit any Industry Nine hubs, also pawls / springs fit all hubs.
XC hubs have the logo/text going left to right across the hub, Enduro hubs have the writing wrapping around the hub shell.
If you have an old XC hub with 5mm allen key fittings inside the axle, you will need a new axle to use any of the conversion kits.
The 15mm kits for Enduro hubs require a different axle from the QR or 20mm kits. The axle is included when you buy the 15mm caps.