Kozitos - Extremely Soft & Warm Cover for Your Feet, Snugly Fitted to Your Bed. Kozitos is a luxurious, pocket cover specifically designed to warm your feet in your bed. Installed under your flat sheet and bedding for extra warmth for your feet. Simple to install - simply slide the elastic straps under the mattress and adjust it for your height. Easily slip your feet in for comfort and warmth. Our innovative, patent-pending design keeps it snuggly in place.