Over time, your original rubber gasket will compress, dry out, and crack. Easiest way to tell your gasket is on its way out? Your portafilter leaks a little around the group or you have to crank your portafilter all the way over for a good seal. Refresh your group with this Caffewerks Silicone Gasket to bring your machine back to perfection. Made from sturdy silicon, these replacement gaskets last significantly longer than rubber OEM gaskets—and hold on to oils and grounds less making it easier to keep clean. This 8mm gasket is just the right size for most home E61 machines.