It means you get both sets of adapters.
As above, the standard bearings are junk, thankfully they are an off the shelf size. I have replaced mine with a set of bearings in the back from a Hope Pro 3 & never had an issue since.
They have a funky preload collar on them which is fairly useless, as bought mine very cheap second hand I did a little bit of experimenting with them and ditched the Easton axles and made up some through work that could be a copy for a Hope design…
Complete reliability now, and bearing changes/axle swaps are a doddle. Worked out lighter than the Easton bits they replaced by a fair chunk too, my carbons are under 1400g now.
I like them, if you can tweak a few little things to improve them, and get a great second hand deal, nothing comes close to them for strength & weight.
If you want an off the shelf super light, strong & reliable wheelset, I would build a set of the e13 TRS rims onto a set of DT Swiss 240 hubs with some DT Revs.
They use a straight pull Sapim spoke, nothing unusual, the nipple is a bit of a pain though. I managed to source a few spares from Germany.