Instrument consists of a rubber bulb pressure applicator, which when used in conjunction with a pressure cuff on the arm, measures systolic and diastolic blood pressure. This unit still has liquid mercury within the metering gauge. The gauge reads from 0 to 260 and is broken up into units of 20 on the meter. The unit is stamp engraved on the outer lid of its wooden box, hinged at one end, and printed: "Med. Dept. U.S. Army." Produced for use during WWI.