A fluid dispenser member designed to be associated with a fluid reservoir (50) and comprising: a chamber (1) in which the fluid is put under pressure, the chamber being provided with an
inlet valve (161, 38) and with an outlet; a dispensing orifice (25); a main
piston (133) in leaktight
sliding contact inside a main cylinder (242) for the purpose of causing the volume of the chamber to vary; a pusher (20) that can be actuated to generate relative movement between the main
piston and the main cylinder; and a differential
piston (31, 32, 33) in leaktight
sliding contact inside the pusher for the purpose of selectively unmasking the outlet of the chamber; said dispenser member being characterized in that it further comprises
stroke-limiting means (28, 39) for limiting the
stroke of the differential piston in the pusher, said
stroke-limiting means being provided between the pusher and the differential piston.