The Bundeswehr used many items resembling their war-time counterparts. These are the gaiters meant to be used with the low boots.
Note: unlike on the picture, some of these are used, and the details vary a bit, depending on the year of manufacture and the factory, yadda yadda. All are the real deal and essentially the same stuff.
During the war, when the production of the jackboots became too expensive, the Germans switched to the combination of low boots and gaiters. Compared to the other countries' equivalents, these are actually pretty good.
These are about 15cm / 6" high strips of thick canvas, with leather reinforcements in critical spots, and two metal buckles and leather straps each.
These were produced in the 1950s and '60s for the West German Bundeswehr. They are almost identical to the wartime models. Some are used, some unissued, all serviceable.