Use for OMP40-2 OMP60 RMP60 RMP600 material quality：Ruby Ball Ceramic Rod Thread: M4 Spherical diameter：5mm(0.20in) length：50mm(1.97in) Durable and long-lasting: Made of high-quality materials that ensure durability and longevity. Accurate measurements: Equipped with a 50mm（1.974in) Stylus with a 5mm（0.20in） diameter Ruby Ball Ceramic Rod and M4 A-5003-0235, providing precise and reliable measurements. Versatile: The probe tip ball ceramic shaft threaded shank M4 is compatible with a wide range of machines and applications. User-friendly: Easy to use, making it accessible to both professionals and beginners. Resistant to wear and tear: The Ruby Ball Ceramic Rod has a long service life and does not wear the surface from abrasive materials, ensuring consistent performance over time.