The Tencel mattress protector by RiseSleep Accessories features Tencel fibers that are sustainably crafted from raw wood pulp and are known for their long-lasting supersoft feel, a non-slip elastic that is 4-5 times thicker and stronger than the standard elastic, and a waterproof barrier built-in to protect your mattress. The Tencel protector is also designed to be invisible when put on your mattress.