The N-Ferno 6811Z Zippered Rib Knit Beanie Hat provides warmth, as well as the option for lightweight protection from bumps, scrapes, bruises and other minor head injuries. Wear this soft cuffed beanie alone or open the back zippered compartment to add the Skullerz 8945 Universal Bump Cap Insert, Skullerz 8945F(x) Universal Bump Cap Insert with Extra Venting or Skullerz 8943F(x) Hinged Universal Bump Cap Insert (sold separately) for work in cramped spaces. Made with 100%