<p>The damper has a tubular cylindrical body (2) closed by two closing devices to define a chamber (5) containing a magneto-rheological fluid. A piston is fixed to a piston rod (11) guided by a disk (28`) having a guiding surface (29`) inside the closing device (4`). The disk is made of material having porosity such that oil of the fluid passes from the chamber to the surface, while avoiding penetration of metallic particles of the fluid.</p>
