Use for: TP20,TP200 Module Material quality：Ruby Ball Tungsten Rod Thread: M2 Spherical diameter：0.5mm(0.02in) Length：20mm（0.79in） EWL:7mm(0.28in) The direct measuring needle is suitable for detecting simple features that can come into direct contact with the measured surface without obstruction. Tungsten carbide measuring rods have excellent rigidity, especially suitable for measuring needles with smaller ball and rod diameters. Ruby is recognized as the industry standard material for measuring needles. It is one of the hardest materials available at present and suitable for most applications. Due to adhesive wear, it is not recommended to use Ruby probe when scanning aluminum workpiece. The product is very small and easy to break, please use it carefully。