Pavoni Piston Insertion Tool has a tapering bore that gently squeezes the piston sealing rings to the smaller diameter of the cylinder for reassembly. The tool has a counterbore with two lugs to locate and align with the cylinder axis without looking. This simplifies maintenance which encourages regular cleaning and lubricating of the group head and pressure chamber improving hygeine and a long service life. The dimensions suit the Professional and Europiccola models.