Compound Gauge Gauge Type Refrigeration Ammonia Dial Size (In.) 3-1/2 Range 30 Hg Vac to 300 psi Dial Size (mm) 98 Connection Size 1/4 NPT Connection Location Lower Smallest Graduation (PSI) 5 Smallest Graduation (In. Hg) 5 Accuracy (%) +/-3-2-3 Case Material Steel Case Color Black Socket Material Steel Tube Material Stainless Steel Lens Material Polycarbonate Operating Temp Range (F) -40 Degrees to 150 Degrees Manufacturers Warranty Length 1 Year