Specification: Consists of a needle having face area 3/10 sq. cm. and graduated at a distance of 25 cm. The needles point is an integral part of barrel which houses a calibrated spring. The spring is confined in a sleeve. The resistance offered by the concrete mortar is shown on the direct reading scale with a marker ring which holds its position when released. Scale range is 0-50 kg/cm2 when the penetration resistance reaches a value of 35kg/cm2 the concrete is assumed initially set. Supplied complete in carrying case.