Instructions for use: Cover the mattress with a sheet as you are used to. Then turn the mattress upside down. Connect the free edges of the sheet to each other with a tensioner by snapping the flip-flops to one and the other, opposite edge. Use the slider to adjust the length. Gradually snap in all 3 Holder Straps. Turn the mattress back, the Holder Strap will ensure that the sheet stays in place.