Features:The meter is in accordance with technical regulation of JGJ/T23-2001, used for testing of concrete compressive strength within the scope of 10-60Mpa, with the system standard energy of 2.207J, and value indicating system of pointer direct reading. Our concrete resiliometer has been approved as Recommended Product for Engineering Construction By the Ministry of construction.Specifications:Length of pointer: 20.0±0.2 (mm)Friction of pointer: 0.65±0.15 (N)Sphere semi diameter at the end of the flip rod: 25±1.0 (mm)Rigidity of flip tensioned spring: 785.0±40.0 (N/m)Location of flip hammer's hook release: "100" at the scale markWork length of flip tensioned spring: 61.5.0± 0.3(mm)Strike length of flip hammer: 75±0.3(mm)Hop location of the flip hammer: "0" at the graduated scaleFixed value of steel anvil: 80±2 (our products are controlled between 80-81)Standard Configuration:Concrete Rebound Hammer TesterGrindstoneFlip tension springBuffer springScrewdriverInstruction Manual