Barrier Bubble™ lining retains air better than alternative cushioning materials. Polypropylene exterior is moisture-, puncture- and rip-resistant. Co-extruded seams are heat-sealed and burst-proof. Self-seal closure features a tamper indicator. TuffGard™ Extreme—Extra cushioning for greater protection. Seam Type: Side; Flap Type: Square; Trade Size: #2; Security Tinted: No.