Each 96 deep well rack comes with 1.2 mL cluster-strip tube and cap assemblies. Each tube is pre-filled with 0.5 mm diameter Yttria-Stabilized Zirconium Oxide beads. Y2O3 + ZrO2 has high density and has extremely high hardness making this matrix ideal for cracking of very tough cell walls, while it's smooth surface minimizes shearing. These Lysing Matrix racks are optimized for the FastPrep™-96 Instrument and are included in the FastDNA™-96 Soil Microbe DNA Kit, the FastDNA™-96 Fungal/Bacterial DNA Kit, and the FastDNA™-96 Fecal DNA Kit.