Replacement elastomer gaskets for old or new SILCA pumps that offer a longer life expectancy than traditional rubber. Used in three original brass chucks (Art.24.4, Art.84 and Art.323) Used in Impero frame pumps Can be flipped for Presta or Schrader (brass chucks only) Utilizes a high-tech, fully synthetic elastomer base material Features five times the durability of traditional rubber materials Silca Pump Head Parts Pump Part UPC: 853740005336