If you are lucky enough to own the oversized 20mm version of the DT Swiss 240s hubs then DT has you covered with a variety of endcaps to convert your hub to your choice of retention systems from the DT Thru Bolts to Quick Release to the 15QR/E-Thru Axle System. 15QR is a new standard centered around a 15 x 100 thru axle system engineered by Shimano in conjunction with Fox. The benefits are simple -- it's all about strength and stiffness. Fox touts a 15 percent increase in torsional stiffness (twisting action), and a 25 percent increase in transverse shear stiffness (bending action). All this while still being lighter weight than 20mm thru axle systems makes it a very sensible choice for many riders. The DT Swiss 15QR/E-Thru Endcaps allow you to convert your 20mm thru axle hub to accept 15QR forks.