Save even more time with this single window #6 self seal envelope. Each envelopes comes imprinted with your return address and you have the option to add you company logo at no additional fee!. This single window envelope has a self seal flap that seals quickly and cleanly. Envelope size 6 1/2 x 3 5/8 Window size 4 1/2 x 1 1/4 Window placement 7/8 from left and 2 inches from top.