Business Source Envelope, Dbl Win, No. 8-5/8", 3-5/8" x 8-5/8", 500/BX, WE (BSN04650) Box of 500No. 8 5 8 check envelopes offer double windows for return address and mailing address. Poly windows and inside tint deliver privacy of contents. Self sealing design makes them quick and easy to close. 24 lb. envelopes require no moisture to seal. Unique double flap design keeps the gum from sticking before use. Simply raise the lower flap and press. General Information Manufacturer: Business Source Manufacturer Part Number: 04650 Brand Name: Business