GLBR400 by Dixon Valve | Liquid Filled Gauge | Lower Mount | 2-1/2" Face | 1/4" Lower Mount | 0-400 PSI Range | BrassFeatures: 2 1 2% accuracy on 2 1 2"; 1% accuracy on 4". Brass movement with highly polished bearing surfaces. Materials: Window: acrylic with membrane assembly. Bourdon tube: copper alloy. Glycerin filled. 2 1 2" face gauges: solid cast brass case with polished ABS cover ring. 4" face gauges: cast brass, silver painted case with chrome plated brass cover ring. Specifications: Ambient temperature range: 4F to 140F ( 20C to 60C) Term Meanings: Figure