- Designed to look great and protect your bike thru-axle from bumps and scrapes. These end caps come in seven color options to show off your personal style! They press directly into both ends of Wheels Mfg thru-axles adding just the right amount of bling on both sides of your bike. - 6061- aluminum - Sold in sets of 2 end caps - Designed, machined and tested in Colorado, USA