Small Resin Cassette holds a full set of 12 instruments. Exterior Dimensions 4.5" x 8" x 1.5" The resin cassettes should be cleaned on a 6-month basis. They may be submerged in a solution of two cups bleach to one gallon of water (0.5 liters bleach to 4 liters of water) for 5 to 30 minutes. If staining has occurred, use less water and more bleach. If bleach does not break through the stain, wipe cassettes with isopropyl alcohol prior to bleaching. Be sure to remove instruments before placing cassettes in bleach solution as bleach is destructive to metal. This cleaning procedure is only recommended with resin cassettes. If staining does occur on stainless steel cassettes, wipe clean with soap and water. DO NOT use bleach process described for resin cassettes on stainless steel cassettes.