a parison stick is used with an injection - blow molding machine for injection - blow molding of a hollow article of plastic material from a parison of this plastic material . the stick has three axially - contiguous portions . the portion connects the parison stick to the injection - blow molding machine . the portion positions the parison stick in the wall of a mold within the machine . the portion terminates in the cavity of the mold and includes distinctly and axially - spaced first and second openings through which gas blows and inflates a parison previously injected around this portion . the openings are connected to a gas - feed chamber via at least one channel . the parison stick further includes at least one obturator connected to an actuator which is controlled by a control member of the machine .