Polyethylene shell construction. Air holes on both sides for ventilation. 4-point standard Durashell easy adjustment suspension. This lightweight working cap is great for full time outdoor activities in low-risk workplace. This cap is NOT designed to meet ANSI Z89.1-2009 standard. Use only to protect from minor bumps and scalp lacerations. Chin strap (Item# HH-ST1406) NOT included, available at $4.00/R per piece.