Looking for a single window imprinted security envelope that you can customize the wording on the font of the envelope? this single window security tint envelope is the perfect choice. It keeps confidential information from showing and has a gummed flap that seals securly when moistened. Envelope size 8 7/8 x 3 7/8 Window size 4 1/2 x 1 1/8 Window placement 9/16 from left and 1 inch from bottom.