Hope has delivered the benchmark in disc compatible rear hubs with the Pro 4. Their hubs have proven a reputation for bullet proof quality, time and time again.
When fitting an SRAM cassette to an XD driver body, you must first remove the drive side spacer before fitting the cassette. This allows the spline tool to go all the way in, to engage the full spline. Pull off only the spacer with a suitable grip and fit the cassette to manufacturer’s specified torque. Then just push the spacer back onto the hub. The same applies to removal of the cassette