Self-Seal Double Window Envelope. Just Press to seal. Security-lined for confidentiality Envelope Size: 8 3/4 x 3 5/8 Upper Window 3 3/4 x 7/8 and 3/8 from left and 2 5/16 from bottom. Lower Window 3 3/4 x 15/16 and 3/4 from left and 11/16 from bottom. This envelope works with QuickBooks Accounting Software Call Office at 1.800.379.7969 for large quantity orders Quantity of 1000 envelopes per 1 item ordered.