If you're repairing and disassembling an original porta filter for an ESTRO PROFI, take particular care when removing the screw that contains inside of it the long spring (looks like the sort of spring that's inside a ball point pen) - this screw is on the undersurface of the porta filter handle. There is a very small plastic (white) stem (looks like a small mushroom) which is necessary to block the hole that's on the topside of the filter (you can see this "hole" once the basket containing the coffee is removed). It's easy to lose this SMALL PLASTIC MUSHROOM part when you disassemble and clean the device. If you lose this plastic mushroom, the coffee will come thru that screw hole containing this spring and it won't have crema and will be quite weak.