The Caffewerks replacement gasket for E61 group head espresso machines is made from odorless and tasteless food-grade silicone. Silicone gaskets are known to last much longer than rubber gaskets before needing to be replaced, as well as not recreating the odor that rubber gaskets can produce over time. The 8mm gasket is thinner than the 8.5mm gasket, creating a seal sooner than stock rubber group gaskets and engaging more smoothly when tightening the portafilter into place. We strongly recommend the use of Molykote Dow-111 Food-Safe Lubricant to install your group head gasket. Compatible with most E61 group head machines, including Brasilia, Bezzera, Expo Bar, ECM, Faema, Gaggia/Gaggia Classic, Isomac, IZZO, Lelit, Orchestrale, Profitec, Rocket, San Remo, Quickmill, Synesso.