3M™ Non-Printed Zipper Closure Packing List Envelope NPZ-XL is a 10in x 12.5in unprinted, clear, polyethylene envelope with a zipper closure for easy and secure open and close. This envelope is designed with a high-tack rubber resin adhesive that sticks on contact to packages. Oil- and water-resistant, this packing list envelope securely protects documents from damage throughout delivery.Keep packing slips, invoices, catalogues, cards and other shipping documents safe and secure with 3M Non-Printed Zipper Closure Packing List Envelope NPZ-XL. This 10 in x 12.5 in clear, polyethylene envelope comes with a zipper closure for open-close and re-open convenience and a high-tack rubber resin adhesive that sticks immediately upon contact. Oil- and water-resistant, the 3M Non-Printed Zipper Closure Packing List Envelope NPZ-XL is built to withstand the toughest handling conditions.