The gun has a swivel operating lever and an outlet section (8) directable onto the object being cleaned. The outlet section contains a drum (10) which is coaxial with the through flow direction (9) of the pressurised fluid. The drum is rotatable and lockable and can bring different nozzles (11) to act sealingly in the outlet channel. Flat seals (12) coaxially enclosing the outlet channel (7) are set in the outlet section opposite the two ends of the nozzles (11) contained in the drum. The gun has locking mechanisms which are provided between the outlet section and drum to correspond in number to the rotary positions of the drum.
