The 252 replace the classic SILCA 25.1 gasket after more than 20 years in the market. This unique gasket borrows from industries which require air-tight seals in the harshest of environments. The 252 gasket utilizes a high tech, full synthetic elastomer base material. It tests to a life expectancy of more than 5X the carbon filled rubber or Buna-N materials used previously. In tests with a major disc wheel manufacturer, the current SILCA Disc Wheel Adapter with 252 gasket excelled by posting a blow-off pressure of 393psi where other designs were unable to reach 120psi. Older versions of the SILCA Disc Wheel Adapter will still benefit for the new gasket, but have a lower hands-free max pressure.