Ergodyne - EGO16811 Made with stretchable, 100 percent acrylic, rib-knit fabric, this 6811ZI Beanie with Bump Cap is a perfect, cold-weather outfit accessory. Fabric creates a snug fit that keeps cold out. Stretchy material provides room for most head sizes yet conforms to your head to trap heat inside. Beanie is designed to fit under headgear for added warmth while working. Zippered compartment holds an included Skullerz 8945 Universal Bump Cap to protect your head from bumps, scrapes, bruises and other minor injuries. This beanie is great to wear during work that involves cold weather or tight spaces where you are prone to bumping your head. Machine-wash to wear the next day.