Standard Half Round gauge plates are screen printed black alkyd enamel on white coated aluminium. The aluminium is H34 5005 and the gauge plates are 0.6mm x 1000mm x 130mm with the markings allowing depths to be measured at 10mm increments. The Gauge Plates are supplied half round for mounting on an 80mm round pipe. The Gauge plates are used as a manual method of measuring dam and flood water depths.