Screw lock rings are also referred to as King Size Rings and are available in sizes up to 10". They are typically used to bind carpet swatches, rug swatches, material swatches, floor covering swatches, and other sample swatches. They can be used to fasten point of purchase displays and many other items that need to be able to rotate around a ring for displaying items. Like loose leaf rings they offer a 360-degree turn. They are conveniently shaped in a "D" formation to hold the bound items in an organized fashion. A screw lock is provided for easily updating yet holding secure of the swatch or other displayed items. All screw lock rings are sold in packages of 10 rings. The hole for the ring should be 1/4" in order for the ring to fit into it properly. This will not allow the hinged part to fit through the hole but it will fit over the screw lock part. Please call us with any questions before placing your order.