SMOOTH & SAFE: Sheet Holders have smooth surface which keeping the sheets in place. It's smooth and skin protected. Just feel free to put it in any side of bed sheet.EASY TO USE: Hold the sheet tightly over the mattress bead with one hand, then point an open end of the gripper at a 30 degree angle to the bed (make sure the slot is facing the bed). Use firm pressure move the gripper in a sweeping horizontal motion until it is fully engaged onto the bed. You don't need to re-fit the sheet in the mid night or morning.DURABLE & REUSABLE: High quality of material in ABS hard plastic, not bendable. Gripping your bed sheet firmly. Once installed, won't get off easily. Making your sheet tidy and smooth. It can be reused if you want to change bed sheet.FOR ANY SIZE OF BED: Set of 12 Pieces, suitable for twin full queen king size. Keep sheets in place and tight.NOTE: Fit for various mattresses with raised eduges. Not suitable for bed without bedside strips or the bedside strips are too small.