There are at least 3 original SILCA brass chucks that use this gasket as well as the IMPERO frame pump. However, none of them were as widely sold as the Presta Only chuck and we had been unable to find original 323 gaskets that were unused and in near original condition to assess performance, so the team at SILCA had to completely redesign and optimize this part from scratch.

This modern 323 gasket has been developed using the same high-tech fully synthetic elastomer used on our modern 242 gasket on the SuperPista ultimate. We find that this material allows for greater valve holding power, greater sealing and significantly improved life expectancy. New 2-stage Seal Design improves high pressure performance and also makes it unnecessary to press the chuck on as far as the original design required.  With a 323 gasket your classic SILCA pump will literally perform BETTER than new!