400 micron Acid Washed Zirconium Beads, 250 gm 

The best choice of beads for disrupting yeasts by bead beating, 400 µm acid washed Zirconium Beads (Zirconium Silicate) are a good choice for applications requiring denser grinding media. Zirconium beads are more dense than silica yet less expensive than stainless steel. Acid washed zirconium beads are treated with acidified water to remove fine particles, dust, and other impurities typically found in untreated beads. They are further baked to drive off organic impurities.