M4 Threaded Styli Straight styli are designed to inspect simple features where direct, unobstructed contact with a measured surface is possible. A ceramic stem is lightweight yet very stiff and offers built-in crash protection. Ruby is regarded as the industry standard for stylus tips. It is one of the hardest materials available and suitable for most applications. NOTE:It is a substitute, compatible with Renishaw A-5003-2764 Specification Ball material:Ruby Ball dia. mm (in.):6.0(0.24) Length mm (in.):75.0(2.96) Stem dia. mm (in.):4.5(0.18) EWL mm (in.):63.5(2.51) Package:1pc