Baseball Cap Crown Inserts: This product is designed to provide internal support for your baseball cap, ensuring it maintains its shape and looks its best. Package Contents: You will receive a total of 30 hat crown inserts; 26.5cmx9cm/10.43inchx3.54inch, size and quantity to meet your daily use. Premium MaterialThe baseball crown inserts are made of quality plastic material, lightweight, with smooth surface, easy to clean, flexible, and not easy to break. Plastic Hat Liner Support: This liner support helps to maintain the crown shape of your hat, keeping the curvature full and making it look like a hat. Ideal for Keeping Your Baseball Cap: With this hat inner support, you can repair or maintain the shape of your baseball cap, ensuring it always looks its best. Specification: Material: Plastic Size Chart: 26.5cmx9cm/10.43inchx3.54inch Package Includes: 30 Baseball Crown Inserts Note: Please allow slightly errors 1-2cm differences due to manual measurement.