The next generation of best-selling Skullerz 8945 Insert, the 8945F(x) Universal Bump Cap Insert with Extra Venting delivers enhanced breathability and up to 35% more crown impact protection. This lightweight and breathable impact-resistant shell easily inserts into any baseball cap, hat or other headwear for protection against bumps, scrapes, bruises and other minor head injuries. With flexible sides and convenient trim-to-fit customization, this bump cap insert easily fits a variety of hats\/caps and head shapes. The shell is made of lightweight, durable polyethylene with a ribbed top for stronger crown impact protection. All-over venting maximizes airflow for cool comfort, while an interior foam pad reduces impact without absorbing odors for fresh all-day wear.