A nozzle assembly (10, 40, 48) configured to atomize a fluid along a fluid axis (102, 302, 402, 502), the nozzle assembly (10, 40, 48) comprising: a fluid outlet extending along the fluid axis; (102, 302,402, 502) 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 (102, 302, 402, 502); an atomizing inlet configured to receive a pressurized gas; and an adjustment member (150, 350, 450, 550, 750) located on the nozzle assembly (10,40, 48) 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 (150, 350, 450, 550, 750) is movably coupled to an opposing base member (152, 352,452, 552, 752) wherein at least one of the adjustment member (150, 350, 450, 550, 750) and the base membe (152, 352, 452, 552, 752) includes a pressure aperture (154, 172) permitting selective communication between the atomizing inlet and the atomizing aperture, and further wherein: (i) in the non-atomizing position, the pressure aperture (154, 172) is substantially occluded; and (ii) in the atomizing position, the pressure aperture (154, 172) is not substantially occluded: characterised in that, the fluid outlet is located at a working end of a pressure cap (114, 514, 714), wherein the pressure cap (114, 514, 714) has an annular ridge located near its rear terminal edge in an interference fit with a complementary receiving groove on the base member (152, 352, 452, 552, 752), wherein the receiving groove allows relative rotation between these parts about the fluid axis (102, 302, 402, 502) while preventing spontaneous disengagement; and wherein the adjustment member (150, 350, 450, 550, 750) is held captive between the base member (152, 352, 452, 552, 752) and the pressure cap (114, 514, 714). a fluid outlet extending along the fluid axis; (102, 302,402, 502) 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 (102, 302, 402, 502); an atomizing inlet configured to receive a pressurized gas; and an adjustment member (150, 350, 450, 550, 750) located on the nozzle assembly (10,40, 48) 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 (150, 350, 450, 550, 750) is movably coupled to an opposing base member (152, 352,452, 552, 752) wherein at least one of the adjustment member (150, 350, 450, 550, 750) and the base membe (152, 352, 452, 552, 752) includes a pressure aperture (154, 172) permitting selective communication between the atomizing inlet and the atomizing aperture, and further wherein: (i) in the non-atomizing position, the pressure aperture (154, 172) is substantially occluded; and (ii) in the atomizing position, the pressure aperture (154, 172) is not substantially occluded: (i) in the non-atomizing position, the pressure aperture (154, 172) is substantially occluded; and (ii) in the atomizing position, the pressure aperture (154, 172) is not substantially occluded: characterised in that, the fluid outlet is located at a working end of a pressure cap (114, 514, 714), wherein the pressure cap (114, 514, 714) has an annular ridge located near its rear terminal edge in an interference fit with a complementary receiving groove on the base member (152, 352, 452, 552, 752), wherein the receiving groove allows relative rotation between these parts about the fluid axis (102, 302, 402, 502) while preventing spontaneous disengagement; and wherein the adjustment member (150, 350, 450, 550, 750) is held captive between the base member (152, 352, 452, 552, 752) and the pressure cap (114, 514, 714).