La Pavoni Duschwand��& Gruppenkopfdichtung Post Mil 51mm Gruppenkopf Europiccola
(Not Q grouphead though, if there is a Q at the end of the model code i.e. ELQ, you require a different grouphead gasket. Numbers 81 & 82. This will either restrict the flow of water or allow ground coffee back into the piston and beyond. ).