These safety mailers are the perfect solution for mailing coins and other delicate objects. Just insert the coins or other items into the mailer and fold in half. Adhesive on the mailer sticks to the opposite side but not the enclosed items. The #10 size measures 3 3/4 inches by 9 inches when folded. They are sized to fit inside a business size envelope or #0 bubble mailer and are ideal for slabbed or raw coins.