It is a replacement stylus tip for blum cnc touch probes. M4 D6.0mm L100mm Cearamic Rod， Hollow measuring rod It Can Replace Q-Mark TM4-60103-C-BL-TC50/51 It Can Replace BLUM P03.8000-010.100.06/143428 This is a spherical stylus with a diameter of 6mm, used for blum CNC touch probes. It is made of high-quality stainless steel and ceramic rods, with a polished surface that gives a comfortable feeling. The handwriting pen is 100 millimeters long and has M4 thread. It is compatible with Blum brand CNC touch probes and is an excellent tool for precision work.