The SDI Diagnostics Safe-T-Chek™ One-Way Valve Cardboard Mouthpieces (Case Configuration) are premium, single-use pulmonary testing accessories engineered specifically for low-risk, asymptomatic expiratory screening. Manufactured by SDI Diagnostics, this specific product code designates the master shipper case configuration, providing high-volume medical facilities with a bulk supply of protective, valved mouthpieces to safeguard delicate testing hardware and prevent patient cross-infection.