Chicago screws: 5 sizes, 16 sets for each size, 80 pieces total. Different sizes: Post diameter is 5 mm; post lengths are 6 mm, 10 mm, 12 mm, 15 mm, and 18 mm; screw head diameter is 9.5 mm. Packed in a clear plastic box with partitions for each size, allowing quick and easy access to components. Wide application: Suitable for leather crafts, bookbinding, documents, books, albums, and more. Material: Carbon steel. Color: Silver. Package Contents: 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), 1 transparent storage box. Only the items listed are included; other items are not part of this package. Note: Due to lighting and display differences, the actual color may vary slightly from the image. Measurement may vary by up to +/- 1-3 cm.