Supports the following standards: ASTM C138, ASTM C192, ASTM C31, ASTM C878, AASHTO T23, AASHTO T97 Lightweight square-head model is used for vibrating concrete test cylinders and molds in the laboratory or field. Unit is flexible-shaft type, powered with 3/4 HP electric motor. Shaft is 24" (610mm) long; vibrating head is 1" sq x 13" L (25 x 330mm) with a speed of 10,000 vpm. 115V model is 7 amps 1ph and 230V model is 3.6 amps 1ph.