Ergodyne - EGO23401 Skullerz 8946 Standard Baseball Cap pairs with a bump cap insert (not included) to wear on work sites where hard hats aren't required, but added head impact protection is still needed. To shield against bumps, scrapes, bruises and other minor head injuries, cap must be combined Skullerz 8945 Universal Bump Cap Insert that is a lightweight, impact-resistant shell featuring an interior foam pad for additional impact protection and comfort. Reflective piping on cap brim helps keep workers safe and seen. With adjustable hook-and-loop closure, one size fits most. Machine-washable, mesh back half offers increased airflow and cooler feel for breathability.