The Ametek/US Gauge 175071K is a 1986 SOLFRUNT Series process gauge with a 200 psi pressure max, 4.5" dial size, 1/4" NPT lower mount connection, monel wetted material, and plastic case material. The Model 1986 gauge is typically used for HF service (hydrofluoric acid) during the alkylation process at a refinery. This gauge has a black glass reinforced thermoplastic (PBTB) turret style case for chemical and petrochemical processing applications. This model comes with an EZ Fill field fillable case standard. No extra parts are needed to make this gauge a liquid filled unit, simply remove plug and fill with glycerine, silicone, mineral oil or Halocarbon.