What kind of Freehub body is this? It looks like an old Uniglide but the threads go all the way down, and it's very short (as I hope you can tell with the ruler). It's on an unbranded hub attached to a DT Swiss X450 rim.
1 Answer
It's a singlespeed cassette hub, made for running a singlespeed cassette cog and a stack of spacers to dial chainline, plus its external lockring pictured.