Feature●Suitable for use with Spex SamplePrep high-energy Mixer/Mill grinders●Compatible with 1/8" (3.2 mm) methacrylate grinding balls 04575-92, 3/8" (9.5 mm) methacrylate grinding balls 04575-88, and 1/2" (12.7 mm) methacrylate grinding balls 04578-19●Recommended mixing/grinding load: 5 mL●1 year warranty●Use with high-energy Mixer/Mill grinders to pulverize and mix samplesDescription Order methacrylate balls to use with disposable plastic vials. Disposable grinding vials are ideal for pulverizing soft, brittle materials and for mixing liquids and powders. Hardness: Mohs 1 ½ Typical composition: Major Element ? C