Securely transport confidential documents, money, and other materials—these bags show clear signs of tampering if they have been opened. Unlike other bags with unreliable adhesives and burdensome keys, these are sealed with locking pins or tags. All have serial numbers on the bag or tag, so you can verify that the receiver got the correct bag. Made of polyethylene or PVC, these bags are strong enough to resist tears and punctures. They also repel water, oil, and solvents to keep contents dry.

Disposable bags are designed for one-time use. All have locking pins that you push into place to create a secure seal. To remove the contents, the bags must be cut open. All of these bags have a write-on address area.

To help reduce waste, reusable bags can be used multiple times. All require locking tags (sold separately) to secure the contents. To use, zip these bags closed and then insert a tag to lock the zipper in place. To remove the contents, the tag must be pulled out of the zipper. The tag will break when it’s pulled, so it can’t be reused. All of these bags have a pocket for inserting an address slip.