These self adhesive card board #10 envelope mailers provide an easy and convenient was to ship your coins. Each mailer measures 7 3/4 x 8 5/8 inches and folds in half to fit comfortably within a standard #10 mailing envelope. The board is made of a cushioned fluted corrugated acts as a pillow for the contents. Sturdy adhesive is strong enough to keep the mailer closed, but can be reopened if needed.