Hub comes with 15 mm end-caps.
Optional 110 x 15 mm Torque-caps (oversized to work with SRAM forks).
Optional 110 x 20 mm Boost end-caps.
Optional 110 x 9 mm Boost QR end-caps (if you can find a fork to fit it).

Hub is not compatible with 110 x 20 mm Non-Boost due to the disc flange being 5 mm further from centre-line.