I believe these two razors to be Wuttig Apparatebau's however there are no manufacturers markings anywhere in the razor's themselves.
They use the flexing of the blade to keep the blade tension. As the topcap is loosened the blade flattens out, however the difference here is that the handle has a internal notched ring, the twist knob has a small protruding pin that clicks into them.

There is a post on a German forum which shows a small instruction pamphlet which, when translated by "Google" says:
With this razor, the blade can be adjusted for any beard growth. It is also recommended with a tightened blade pre-shave and shave sharply at notches 1, 2 or 3.

There were two versions - one in Silver and the second in Gold.
(Click on either the images or the description below to take you through to the individual page.)

If anyone has more information, please contact me.

Wuttig Apparatebau Silver Version	Wuttig Apparatebau Gold Version