One doesnt have blueing on the tang. I'm assuming the blueing is more popular so the first 2 sales get the blueing unless you specify otherwise in the comments when ordering...
This knife is a knife in the werkgericht line.
Werkgericht knives are a line of knives that are durable, high performance and budget friendly. They are always monosteel blades with a polished spine and choil, with a ku finish and satin bevels. The handles are polished ebony.
 
Here's some specs on this particular blade:
shape: Gyuto with fairly round edge profile
blade length: 250mm
blade height: 63mm
steel: O2
weight: 267g
type of grind: Midweight, leaning workhorse. Absolute beasts.