Multi-Language 10x13 Thank You Poly Mailers Self Seal Mailing Envelopes Pack of 25 USPS APPROVED FEDEX APPROVED UPS APPROVED Made with durable 2 Mil thick polyethylene, these envelopes resist punctures, tears, and damage from water, dust, and dirt. Despite their strength, these poly mailers are incredibly lightweight, making them perfect for those looking to save money on postage compared to traditional cardboard boxes. Pack of 25 Size: 10x13 Durable 2 mil poly material for resisting tears, punctures, and damages. Hassle free, self-sealing adhesive. Lightweight mailers for economical postage. Excellent proficiency mailers perfect for shipping a wide variety of non-fragile items. Customer satisfaction guaranteed. Please do not hesitate to contact us with any questions or concerns.