Andux Land Sheet Suspenders Adjustable Fitted Sheet Straps Grippers Mattress Cover Corner Holder Elastic Straps Fasteners Clips Clasps CDJ-01 White 4 straps, one used diagonally for each corner of the bed. Great For Bed Sheets and Mattress Covers. Metal Clasps For Secure Grip. Lift mattress and fasten one clip to edge of sheet . Repeat above for all 4 corners. Keep bottom sheets on all mattresses, even hide-a-beds, adjustable beds, inclining beds, baby's cribs and more.