The Venturi 51mm dosing funnel is manufactured from high grade stainless steel. When placed on top of the portafilter whilst grinding directly into the basket, the Venturi dosing ring acts as the perfect portafilter dosing funnel catching all the coffee grounds that may have otherwise found their way onto the bench from the grinder. It has an additional 6 magnets built into te base to help hold the unit in place when grinding. Its 51mm size is the perfect size for all post 2000 La Pavoni lever machines.