Our Chicago Screws are perfect for securing straps, or thick areas on purses, backpacks, wallets, and more. This hardware is durable, and looks great from both sides. This hardware is unique, and the threaded posts allow for easy installation, without any setting tools.- Small: 3/8in (10mm) wide caps by 1/4in (6mm) high posts- Medium: 3/8in (10mm) wide caps by 5/16in (8mm) high posts- Large: 3/8in (10mm) wide caps by 3/8in (10mm) high posts