Air holes on both sides of cap for ventilation. - Polyethylene shell construction. Bump Cap Features Head Circumference: About 56-60cm (Adjustable). Size: One Size (Adjustable). Pattern: Solid. Color: red/black/grey/dark blue/sapphire/orange/brim red/brim black/brim grey/brim navy blue/brim sapphire blue/brim orange.
