Pacer's S Series self-priming centrifugal pumps are light-weight and chemically resistant for general service on water, salt water, waste water, mild acids and bases. This is our most popular pump across multiple markets. They feature stainless steel internal fasteners, Viton?, EPDM or Buna O-ring with stainless steel external fasteners. There is a non-metallic option which minimizes solution contact with internal metal parts. The pumps are molded of tough, glass-reinforced polyester, polypropylene or Ryton?. Polyester models are available with or without lined volute for abrasion resistance.