HEAT-ACTIVATED CUSTOM FIT: The only reusable earplugs with patented Conforming Material Technology (CMT); uses body heat to match the contour of the wearer's ear canal for a unique custom fit SIMPLIFIED INVENTORY: CMT design ensures SmartFit Earplugs can adapt and fit virtually any ear canal shape and size; this simplifies your ear safety inventory control as one size fits all UNPARALLELED COMFORT: CMT design combines with soft TPE material to deliver maximum comfort and wearability throughout the day DETACHABLE CORD & CASE: Unique detachable nylon cord system adapts to virtually any work application; HearPack storage case keeps corded earplugs clean and helps prevent loss or misplacement NRR 25: Three-flange design and Conforming Material Technology combine to deliver good ear safety and a Noise Reduction Rating of 25; 100 pairs per pack