DOUBLE WINDOW SECURITY ENVELOPES; tired of cheap paper envelopes that can be easily seen through?. Each envelope contains two front windows, a 1″ X 3-1/2″ top window positioned 1/2″ from the left and 2-1/2″ from the bottom and the bottom 1-1/8 X 4″ window is 1/2″ from the left and 3/4″ from the bottom.