Securely mounted with Hook-and-Loop fasteners under the mattress. The best Satin Low friction Sliding Material on the market. Non-Skid Material along the sides. The Satin material only slides sideways therefore the person does not slide downwards. The Small, Medium and Large Silk Masters are to be fitted on top of an ordinary sheet – preferably an envelope sheet – to help the person with the manual transfer. The X-large model does not need a sheet underneath. Ideal for the more-self-reliant person.