Hanes Men's Knit Boxer With Comfort Flex&reg; Waistband 4-Pack # 548BX4 cotton boxers closure 100% pure, soft cotton for all-day comfort (Heathers cotton/polyester). Comfort Flex waistband is super soft and moves with you. Fly won't gap - we guarantee it, or your money back. Fiber Content: Solids: 100% Cotton; Heathers: 75% Cotton/25% Polyester