Model: 4DFSW18-137-300-3000-AD Key Product Features Advanced Pump Construction 100% Stainless Steel: Entirely constructed from 304 Stainless Steel for maximum corrosion resistance. Water-Lubricated System: Features a water-filling lubricated rotor with high-precision top/bottom graphite bearings and thrust bearings. Durability: Double outer and inner shielding structure with internal coils made from high-temperature tolerant copper wire.