Portable tempature potentiometer double range, two scales 27.500 in. Lg mtd on two turn slidewire, eight position function switch, off, output a, measure a, standardize a, standardize b, measure b, output b, off, one 1.5 v dry cell for measuring circuit, two 4.05 v mecury for detector, removable lid and carrying handle, o/a dim. 12.344in. Lg, 8.906 in. W, 7.562 in. H