TEST SYSTEM, SPORE MAIL-IN ECONOMY (52/BX 4BX/CS) McKesson Sterilizer Monitoring Service For use in Steam, Chemical Vapor, Dry Heat and EO Gas Sterilization processes. Test results available online at www.checkyourtest.com. 24-Hour Incubation All Steam cycles. 72-Hour Incubation Chemical Vapor cycles. Packaged: 52 Tests Per Box, 4 Boxes Per Case CAUTION: THIS PRODUCT CONTAINS NATURAL RUBBER LATEX WHICH MAY CAUSE ALLERGIC REACTIONS.