PEAKs unique straight coil design causes the spring coils to form an inverted V, resulting in a better experience than working with a conventional wrapped spring. PEAKs straight coil has parallel slits which will hold your materials evenly and more securely. The PEAK Material Clip will fit 1/4 diameter shafts. Clips will rotate to any angle needed, and multiple Material Clips can be used in tandem. PEAKs Material Clip is provided with 2 sizes of coil to grip a wider range of materials better