A nozzle assembly configured to atomize a fluid along a fluid axis , the nozzle assembly comprising: a fluid outlet extending along the fluid axis; and including a fluid aperture and fluid side wall defining the fluid aperture ; an atomizing aperture adjacent the fluid side wall and at least partially surrounding the fluid axis ; an atomizing inlet configured to receive a pressurized gas; and an adjustment member located on the nozzle assembly and movable to: (i) an atomizing position such that the atomizing inlet is in communication with the atomizing aperture ; and (ii) a non-atomizing position such that the atomizing inlet is not in communication with the atomizing aperture ; wherein the adjustment member is movably coupled to an opposing base member wherein at least one of the adjustment member and the base membe includes a pressure aperture permitting selective communication between the atomizing inlet and the atomizing aperture , and further wherein: (i) in the non-atomizing position, the pressure aperture is substantially occluded; and (ii) in the atomizing position, the pressure aperture is not substantially occluded: characterised in that , the fluid outlet is located at a working end of a pressure cap , wherein the pressure cap has an annular ridge located near its rear terminal edge in an interference fit with a complementary receiving groove on the base member , wherein the receiving groove allows relative rotation between these parts about the fluid axis while preventing spontaneous disengagement; and wherein the adjustment member is held captive between the base member and the pressure cap . a fluid outlet extending along the fluid axis; and including a fluid aperture and fluid side wall defining the fluid aperture ; an atomizing aperture adjacent the fluid side wall and at least partially surrounding the fluid axis ; an atomizing inlet configured to receive a pressurized gas; and an adjustment member located on the nozzle assembly and movable to: (i) an atomizing position such that the atomizing inlet is in communication with the atomizing aperture ; and (ii) a non-atomizing position such that the atomizing inlet is not in communication with the atomizing aperture ; (i) an atomizing position such that the atomizing inlet is in communication with the atomizing aperture ; and (ii) a non-atomizing position such that the atomizing inlet is not in communication with the atomizing aperture ; wherein the adjustment member is movably coupled to an opposing base member wherein at least one of the adjustment member and the base membe includes a pressure aperture permitting selective communication between the atomizing inlet and the atomizing aperture , and further wherein: (i) in the non-atomizing position, the pressure aperture is substantially occluded; and (ii) in the atomizing position, the pressure aperture is not substantially occluded: (i) in the non-atomizing position, the pressure aperture is substantially occluded; and (ii) in the atomizing position, the pressure aperture is not substantially occluded: characterised in that , the fluid outlet is located at a working end of a pressure cap , wherein the pressure cap has an annular ridge located near its rear terminal edge in an interference fit with a complementary receiving groove on the base member , wherein the receiving groove allows relative rotation between these parts about the fluid axis while preventing spontaneous disengagement; and wherein the adjustment member is held captive between the base member and the pressure cap . <EOS>