Measure the hardness of aluminum, aluminum alloys, copper, brass, fiberglass, plastics and other materials in the laboratory, shop or field according to ASTM D2583 using the Barcol Impressor Hardness Tester. One hand operation in any position and an easy-to-read hardness indicator dial make this tester very field friendly. The portable, lightweight (16 ounces) precision, hand-held impressor can even be used in confined spaces, since there are no batteries and no sparking hazard. Model 935 is for softer plastics and very soft metals. Impressors are sold complete with carrying case, adjusting wrench and two spare indentors.