This is a 245mm gyuto with a 1.2519 core and clean iron cladding.  The 1.2519 core steel is German Tungsten tool steel which is quite similar to blue2 (aogami2).  The cladding is a pure form of iron which has been etched reveal the brilliant detail of the iron.  There is a piece of pure nickel separating the cladding and the core steel which minimizes carbon migration and creates an aesthetically silver line. The handle is ancient bog oak with a purple dyed mammoth tooth spacer.
Spine Measurements:
Out of the handle: 3.39mm
Above Makers Mark: 2.78mm
Middle: 2.52mm
4cm from tip: 1.90mm
2cm from tip: 1.37mm
Weight: 214g