The Industry Nine Enduro front hub is their large diameter hub shell. It's bad, it's beautiful, and it can accommodate any front axle type known to man. We sell our Enduro wheels with a 20mm thru axle, but for those of you wanting something different, the Industry Nine Enduro Front Hub Conversion Kit will allow you to do just that. Please Note: If you have an Enduro Hub already configured with a 20mm thru axle and need to make a change to quick release or 9mm thru bolt, you'll simply need the end caps because the axle is the same for all three configurations. However, if you need to convert your 20mm front hub to 15mm, you'll need the 15mm axle and end caps to make the conversion. Inversely, a switch from 15mm to any of the other configurations will require an axle and end caps.