Elastic Straps Fit Most SheetsSheet Fasteners will be able to fit most mattress sheet sizes including: Twin, Twin XL, Full, Full XL, Queen, King and even California King sheets. (See our mattress size chart for reference) AdjustableThe bed sheet straps are also elastic and adjustable. Depending on your sheet size, use the buckles to lengthen or shorten the sheet fasteners. Adjustable to any angle to suit your personal needs, making bed sheet making simple and efficient. Built-in Plastic ClipsPlastic clips for a firm grip. Unlike metal, plastic will protect your sheets from tearing, but will hold the sheets tightly to your mattress without worrying about them coming loose No need to lift the mattressJust fix the 2 clips on both ends to any corner of the mattress. Slide it under the mattress and secure the other end of the clip to the sheet. Avoid the hassle of lifting or flipping a heavy mattress Risk-free PurchaseYour satisfaction is our highest pursuit If you have any questions please feel free to contact us, we will reply you within 24 hours.