Housing die-cast zinc.
Knob thermoplastic PA (polyamide).
Pins and wedge stainless steel.
Leaf spring phosphated bronze.

Housing chromed.
Knob black or orange, glass-bead reinforced.
Pins and wedge bright.

By turning the knob, the pins mounted in the bottom section of the sliding clamp are drawn together by the springs and forced downwards. The two pins press against the surface and fixate the sliding clamp.

The sliding clamps have 2 different operating principles.

Operating principle 1:
The sliding clamp is movable.
The sliding clamp is bolted onto a base plate (21888-15), loose plate or block placed under a fixated rectangular bar. The sliding clamp together with the plate or block can be slid up and down the fixated bar.

Operating principle 2:
The sliding clamp is fixated.
The sliding clamp is bolted onto a fixated plate or block placed under a loose rectangular bar. The sliding clamp cannot move but the bar can be slid up and down over the fixated plate or block.

1) Leaf spring
2) Reading line for scales

Base plates 21888-15.
Scales stainless steel 21880.