... accurate measure and inspection an Rods jewels are made of sapphire/ruby ,they are widely applied to medicine, accurate ... , wearable and high heat conduction environments.Main types:sapphire/ruby rods jewels,single round end rods jewels,double ... surface for application: Rz0.05~ Rz0.2 MaterialSynthetic sapphire/ruby single crystal α-Al2O3, natural agate, spinel, ceramic, etc. sapphire rod jewels