The exact measurement of piston face of this tamper is 49.4mm. Fits the Olympia Cremina, Maximatic, Pasquini Livietta, La Pavoni, Elektra M-Cal, Conti Comocafe, and any other machine that nominally uses a 49mm tamper.
The slightest buff, polish or dressing will take this tamper down to the perfect tolerance for your basket (after all, there is a variance of basket size wth the vintage machines, and factoring a .1mm diameter difference over the entire circumference of the circle means the width of tolerance equal to about 1 grain of espresso grind coffee!). This tamper fits all of the forementioned machines without any changes but we do want to account for any variance of basket size without having to "send off my basket" for a cu$tom fit. Flat bottom, nice, precise square sides, 5mm height at the side of the piston face. One smooth turned piece of stainless steel. Nice balance in the hand, heavy at the piston end, and a very good feel!