10x13" two-sided envelope with puzzle photo in upper right corner. Extensive text below pertains to the fun the family will have assembling the Tom Mix puzzle. Left side indicates that the enclosed puzzle is "Free With The Purchase Of A Large 25¢ Tube/Rexall Milk Of Magnesia Toothpaste." Back of envelope has photo of smiling lady, graphics of toothpaste tube and extensive text with features and benefits of the product. 2" seam split at flap. Center folds and moderate handling creases but still VG and Scarce. 125-piece puzzle measures 9.75x13" when fully assembled. Text at lower right reads "Tom Mix/And His New Horse Tony, Jr. In Universal Pictures." This 1930s puzzle premium is Exc.