Save Time and money sending business mail with our # 10 Double Window Security Envelope Quickly and easily send business mail with our 500 no. #10 envelope with cost saving gummed flap design. Our gummed seal flap with diagonal seams will work well when stuffing by hand or when using a desktop inserter, thanks to the wide opening that prevents paper from getting stuck during stuffing Once sealed, no adhesive is exposed so you do not have to worry about the envelope sticking to other mail Business mail will be completely secure during transit It can be so difficult to find envelopes that create a strong lasting seal thus forcing you to waste time using glue sticks or tape to close the envelopes. Our durable #10 security double window envelopes with strong adhesives are designed to immediately create a strong seal so you do not have to worry about your contents being exposed to others. Unlike weak sealing envelopes that allow your contents to fail out and become exposed. So much for a security envelope! Our strong seal will ensure the safety of your contents. Security with a Professional Look It can be frustrating to purchase envelopes only to find them flimsy enough to have you worried about their durability during transit. Our durable, smooth 24 LB white wove paper creates a professional look and feel from out of the box all the way to your destination.