Pack of 100 10x13 KKBESTPACK color Pink Poly mailers is polyethylene film. Material is waterproof, seal is not. Stated measurements do not include flap 1. 5 inch. White Outer surface & silver inner layer provides confidentiality. High-efficiency mailers are perfect for shipping A wide variety of non-fragile items. High strength seams allow over-stuffing water tear and puncture dirt resistant. Pressure sensitive adhesive provides a high strength durable closure. Superior tear and puncture resistance. 100% recyclable UPS, FedEx & USPS approved. Lightweight, saves on postage. Fast SHIPPING, buy with confidence.