PureCare elements rayon from bamboo sheets are a soft, sateen woven blend of premium long-staple cotton and lush rayon from bamboo. Designed to provide the ideal fit for both standard and adjustable base mattresses deep, our premium sheet sets feature:- Precision-Fit(TM) corners for a clean, crisp fit on the fitted sheet- A Precision-Fit(TM) elastic cuff which prevents your fitted sheet from slipping off your mattress - Enveloping pillowcases that secure your pillow in the case throughout the night- An additional of the flat sheet for complete coverage sheet set includes: fitted sheet / flat sheet / two pillowcases (one pillowcase for Twin and Twin XL)All PureCare elements sheets feature antimicrobial silver chloride to inhibit bacteria, mold, and mildew that cause deterioration, stains and odors on this product.