... steel color or black color. Detailed Product DescriptionOKE clip knot (spring parts),zigzag spring,sinuous spring,coil spring,sofa ... ,no sag spring,belong to sofa part OKE clip knot (sofa parts), zigzag spring,no sag spring,sinuous ... : (pitch:18, loop height:48)(2) OKE clip knot (used with Zigzag springs) 1).high-tech plastic material ... are made especially for loose cushion upholstery. Clip knot CK-01