The simple soultion to keep sheet in place. Sheet Stay-Downs are like suspenders for your bedding. Simply lift the mattress corner and clamp the strap diagonally 10" down from the corner. Then adjust the length of the strap using the Velcro tab. One strap goes on each corner to secure the sheets and bedding. Fits any size mattress. Made in the USA. Sold as a 4 piece set.