Our series of security bags have unique, self-sealing adhesive strips that form an instantaneous and permanent seal, making it impossible to reopen the bags without destroying them. Some of the notable features of our tough, tamper-evident Evidence Collection and Security Bags are the tear-off investigator's receipt located at the top of the bag, the pre-printed control numbers included on both bag and receipt, and three write-on areas for tracking evidence. The release liner protects the unique, self-sealing gel-glue strips, and a border pattern is printed around the edges to prevent the opening of the bag from the sides. Puncture and tear resistant, our bags are made of a clear 4 mil polyethylene material, providing strength and allowing the investigator to view the contents of the evidence bag. The write-on areas include space for names, contents, chain of custody, and crime lab information. We are sure you will find these evidence bags to be an excellent value.