· #10 LEFT WINDOW ENVELOPES; premium quality, suitable for everyday business and legal mailing.· EASY READ SINGLE WINDOW; perfect for QUICK mailing, each envelope has a premium, extra-large, easy read 4-1/2 X 1-1/8 poly-window, positioned 7/8" from the left and 1/2" from the bottom of the envelope, perfect for displaying addresses or business information, making slow printing and hand addressing a thing of the past· 1000 ENVELOPES SUPPLY; ideal for everyday business use, 2 boxes, each box provides 500 envelopes for a long-lasting supply, each measuring 4-1/8 x 9-1/2 inches, perfect for invoices, statements and many more business uses!· 24 LB White Wove Paper that creates a professional look and feel from out of the box all the way to your destination· Perfect for mailing Invoices, QuickBooks Invoices and checks, billing statements, checks, and other business mail.