Design: They usually look like a standard baseball cap or a low-profile hat, though traditional shell styles exist. [1, 2, 3]
Ventilation: Many feature air holes or mesh panels on the sides for better breathability and comfort during long shifts. [1, 2, 3]
Inserts: You can buy them as a complete unit or get universal bump cap inserts to place inside your own caps. [1, 2]