Abstract: It comprises a distributor body having an output port, a feed port and a return port, and a slider adapted to slide inside the distributor body between a first position isolating the output port from the feed and return ports, a second position connecting the output port to the feed port and a third position connecting the output port to the return port. The slider co-operates with the distributor body to define two pilot chambers fed with a pilot fluid, an output chamber is connected to the output port by an output passage, and a damper chamber in the distributor body includes mechanical means for reducing its hydraulic stiffness and connected to the output port via a damper passage including a calibrated orifice.