Name: Spring Clips Materia:Iron + Fully plastic coated Size: 20mm*22mm*12.3mm Product features:Fully plastic coated to resist spring abrasion. Heavy steel construction keeps clips from opening when springs are in tension. Secure the clips from any angle Hold zig-zag springs of any gauge permanently. Universal four-hole clip used for back and seat construction. Use with either 1 or 3 nails on the lip. Package Content::50pcs*Furniture Spring Clips QUALITY: metal EK, s-clips have 5 separate holes where screws, nails or staples can be used to fix the springs to the frame, with 5 SEPARATE holes allows more catch points to ensure the spring does not tear free from the frame.