It are essential accessories for achieving fine particle size reduction in laboratory sample preparation. These grinding balls feature a polytetrafluoroethylene (PTFE) outer layer encasing a robust steel core, combining the chemical resistance of PTFE with the strength and density of steel. Their 15 mm diameter is ideal for homogenizing and pulverizing samples in Retsch's Mixer Mills, including the MM 200 and MM 400 models. The pack contains an appropriate quantity of grinding balls, ensuring ample supply for multiple applications.