Chicago screw assortment: 5 sizes, 16 sets for each size, 80 Chicago sets in total. 5 different sizes: pole diameter is 3/16 inch/5 mm; 5 kinds of pole length are 1/4 inch/6 millimeters, 3/8 inch/10 millimeters, 1/2 inch/12 millimeters, 9/16 inch/15 mm, 11/16 inch/18 mm; the diameter of the screw and base is 3/8 inch/10 mm. Good quality: made of carbon steel material, plated with silver nickel, sturdy and rust-resistant, easy to bind, install and remove, reusable, provides good sealing. Storage box: packed in a clear storage box with partitions by size, allowing quick identification and organization. Wide application: suitable for leather craft decoration, binding, documents, books, albums, DIY crafts, and other projects. Details: Color: silver. Each screw set includes 2 parts: one post and one cross head stud. Post diameter: 3/16 inch/5 mm. Screw and base diameter: 3/8 inch/10 mm. Post length: 1/4 inch/6 mm, 3/8 inch/10 mm, 1/2 inch/12 mm, 9/16 inch/15 mm, 11/16 inch/18 mm. Quantity: 16 sets per size, 80 sets total. Package includes: 16 sets of Chicago screws (5 x 6 mm), 16 sets of Chicago screws (5 x 10 mm), 16 sets of Chicago screws (5 x 12 mm), 16 sets of Chicago screws (5 x 15 mm), 16 sets of Chicago screws (5 x 18 mm), and 1 transparent storage box. Warning: small parts, keep away from children.