YYST 3-Way Bed Sheet Holder Triangle Model Bed Sheet Fastener Bed Sheet Gripper Bed Sheet Clip (Set of 4) Two Tie Stays for Free ! Quantity : 4 pcs a set Material : Elastic and nickle - plated clamps. the clamps have a fabric protector so no damage to your sheet. triangle model avoids sliding all the time. Suitable for bed sheet ,fitted sheets, flat sheets, mattress pads, and ironing board covers. Each strap is adjustable.