Redi-Seal Insurance Claim Form Envelope, Cheese Blade Flap, Redi-Seal Adhesive Closure, 9 x 12.5, White, 100/Box Sized to fit most types of insurance claim forms without bending or tearing. The single poly window is a useful way to display the recipient's name and address. First Class Mail® print signifies that these are to be treated as First Class parcels at the post office. Self-sealing adhesive helps save time and effort, especially when stuffing a bulk order.