Our 9 x 12 2Mil Tamper-Evident Bags These tamper-evident bags ensure that the bag's contents are not accessed before its intended use. These bottom loading bags are to be heat sealed and will remain secure during transit. The bag contents can be later accessed via a perforated tear notch on the top of the bag. The reclosable zipper top provides an option to reuse the bag. Our Zip Tops offer a surprising combination of clarity and quality without sacrificing the features you demand. These tough bags employ a reinforced side-welded zipper. Made of 100% virgin, Low Density Polyethylene (LDPE) resin, these bags meet FDA/USDA specifications.