It looks like the axle has a bigger diameter, then machined to the smaller normal diameter where the bearings sit, making the inside integrated speed washer... but two-axle system? Does it mean each sides are independent shorter axles and grinding will go through the hanger itself but never see an axle? Would that be strong enough?
¯\_(ツ)_/¯
Weight, height and prices are not that bad though. Including shipping to Canada, it comes at about the same price as Thunder Hollow Lights bought locally, before taxes.
Hopefully the QC is good and they come out with more sizes sooner than later, personnaly 55mm is a bit too high to take the plunge.