I bought this wheels used, and am wanting to replace/repack the bearings, but I can't figure out how to disassemble it. Actually, I'm not even sure if it's cartridge or cup and cone, picture attached.

There's a flat bit on the black part (that might be the cone), and it's probably 16mm. But it's attached to the chrome bit, which might be a lock nut (?), but there's no flats on the it. The axle isn't threaded.

Any thoughts?

The hub is branded "Xlab", which seems to be a triathlon equipment supplier.