The unit consists of two movable frames pivoted at one end. The lateral extensometer is fixed to the specimen with the help of tightening screws. The lateral extension is indicated on a dial gauge of 0.002 mm x 12 mm travel. The extension is magnified 2.5 times and the dial gauge readings are to be divided by 2.5 to get the exact readings. A spacer strip is provided to initially set the dial gauge and can be removed after initial setting. Supplied in a wooden carrying case.