An improved handheld applicator is provided, fitted into an assembly onto a pressure container which is equipped with a gun valve and containing a viscous compound suitable for forming a silicone paste, a polyurethane (PU) foam, or a glue, the applicator being producible in one single injection moulding step and providing in handheld use the ergonomics, the aiming and the dosing accuracy comparable to the use of the pressure container with a dispensing gun. Further provided is a process for the production of the applicator and of the assembly, as well as the use of the assembly for applying a compound from the pressure container with a handheld method.