6.49x9.06 is usable size; external width is usable width 6.49 inch, external length is usable length 9.06 inch and additional self-adhesive part 1.57 inch
The thickness of metallic foil material is 3.4mil (one side)
Self seal design with strong adhesion makes the mailer work for your purpose and not need extra tape to seal
The material of this metallic poly mailers is stronger than shipping poly packaging