Skullerz Universal Bump Cap Insert is a lightweight, impact-resistant shell that inserts into any baseball cap, hat or other headwear for additional head protection. It helps protect against bumps, scrapes, bruises and other minor head injuries. Many hats vary in shapes and sizes, but the flexible horizontal and vertical sides of the shell allow it to fit both a variety of hats/caps and head shapes. The trim-to-fit customization makes it easy and convenient to fit into many types of hats, caps and headwear. The insert is made of lightweight, durable polypropylene and designed with maximum ventilation to provide continuous airflow for breathability but won't compromise protection. It features a foam pad inside for additional impact protection and comfort against the head. It's not bulky like a hard hat and is ideal for mechanics, airline baggage handlers as well as workers in warehouses, factories, in-home services and other industries that do not require safety hard hat protection but work in areas with low beams, pipes, passageways or other low hanging obstructions. Color: Gray.