A rubber group gasket designed for use with Profitec machines. Compatible with the following models: All Profitec Machines with E61 Groups All ECM Machines with E61 Groups All Rocket Espresso Machines with E61 Groups Group gaskets are a common wear and tear item that can dry out and crack over time. We recommend replacing your gasket once a year with typical use, or more frequently if necessary. Failure to replace your gasket will result in a weakening of the seal in your group head and leaking around the sides of your portafilter.