The SILCA 242 gasket is constructed from an innovative fully synthetic elastomer that supplies 5x the life expectancy of classic rubber seals. The design seals against the valve in two seperate positions, helping to keep an air tight lock, and preventing blow offs at high pressure. This seal is backwards compatible with all of the previous Silca 30.0, 30.2, and 17.4 pump head types. compatibility presta valve pump heads

made in the USA