PMSSteriTest® Class 4 Steam Indicator Strips are multi-variable chemical indicators expertly engineered for 134 °C, 3.5-minute steam sterilization cycles. Featuring a dual-strip design and water-based, eco-friendly ink that transforms from blue to black, they provide clear visual confirmation of proper steam penetration. Compliant with ISO 11140‑1 standards and manufactured free from lead or heavy metals, these Class 4 strips are ideal for use inside packs, trays, or rigid containers to ensure reliable sterilizer performance. Each strip measures 13 mm × 170 mm and comes in economical 500-strip packs—perfect for daily monitoring in hospitals, clinics, and CSSDs confident in sterilization quality .