The group head gasket is a boring, but crucial part of the espresso machine. It perfects the seal between the portafilter and your espresso machine. If the seal is not good, you won't be able to build pressure correctly, and your espresso will not taste good. A dirty gasket is just as bad as a tired one, both don't work right. Features Better durability The group head gasket is the most common pieces that wears on an espresso machine. Silicone is longer lasting than NBR rubber. Softer feel Coffee experts prefer silicone gaskets because of the greater compressibility, better seal and easier portafilter locking. See the dirt The light grey color makes it much easier to spot coffee grounds that need to be cleaned. Easy to remove Silicone doesn't stick to the shower screen when it ages. Three grooves make it easy to get a removal tool in. What's up? The top side is marked UP so it's easier to know which direction to put it in for a correct seal. Compatible Fits the DE1 and most E61 machines.