ProChek S is a Class 4 multiparameter internal chemical integrator strip for use as an immediate result sterilization monitor inside peel pouches, cassettes and packs. Indicates penetration of steam and heat inside pouch, cassette or surgery pack. Sensitive inks react to multiple parameters of steam and heat over time. Dramatic color change from yellow to blue-purple when sterilization conditions are met. Immediate results at the end of cycle provide quick feedback.