Usage Air Pump Standard or Nonstandard Nonstandard Pressure High Pressure Material:silicon carbide color:black Usage:high-precision plunger for rotary plunger pumps,hydraulic pressure valve,super high pressure oil pumps. Characteristic:resistant to strong acid,strong alkali,salt and gas or deletetious,ZrO2 plunger has long life ,high toughness,resistant to wear. plunger