The Berkeley Custom Shaver dates back to the 1940's / 1950's
It has a ribbed top cap and safety bar. The handle has two compartments in it that hold blades. There is an adjustment knob that also holds everything together.
The adjustment "mechanism" is a simple spring steel shim.

How does it shave? I'm so used to shaving with a handle but once you get around the weird feeling that you are shaving with a block, it gives an excellent shave.