Biological Indicators Provide the Best Assurance of Sterility - Used for Load Control Monitoring - Consists of Bacillus Stearothermophilus spore strip, sealed glass ampule with growth medium and a bromocresol purple pH indicator system, brown color-coded cap with holes for sterilant penetration and a hydrophobic filter as a bacterial barrier, and a chemical indicator on the label that changes from rose to brown when processed - Sold by the Box - 25 Indicators/box