Applicator has at least one barrel (4, 5); a piston (6,7) moveable between a variable first position and a second position (not shown). Movement of the piston towards the first position by biasing means (18, 19) draws fluid into the barrel; movement towards the second position by actuating means (3) forces fluid out of the barrel. Fluid inlet valves (14, 15) and fluid outlet valves (16, 17). A dosage control part (20, 21 ) (adjustable stop) is slidingly lockable in slotted component (22, 23) of body (1 ); and abuts an abutment portion (24, 25) to define the first position of the piston and therefore the dosage of fluid. User sets the dosage of the applicator via the dosage control part. Manifold (54) is in fluid communication the inlet and outlet valves. Lever portion (38, 39), accessible from an exterior of the applicator, allows user to move piston independently of actuating means (3).