Four pieces in 100% rayon derived from bamboo: a 90″ x 102″ flat sheet, a 60″ x 80″ fitted sheet with a 16″ pocket, and two 20″ x 30″ pillowcases. The first thing you notice is temperature. Bamboo viscose has a smooth filament, so the fabric feels cool the moment you lie down and stays that way, rather than warming up under you the way a dense cotton sheet does. It also moves moisture along the cloth instead of trapping it, which keeps the surface dry — the part that actually matters at three in the morning. The fitted sheet has a 360° elastic band around the full hem, so it holds on a deep mattress or one with a topper. Pillowcases close with an envelope flap to keep the pillow in place. Care is straightforward: machine wash cold, tumble dry low, remove promptly, no bleach or dry cleaning.