Save time and money by sending business mail with our #10 single pistol window envelopes. Quickly and easily send hundreds of business invoices, bill statements, and checks with our #10 envelope design and cost-effective gummed seal. The gummed flap with thick adhesive makes for quick and easy mass mailings. Mail business statements, invoices, or checks in bulk with enough room for no. 8 or no. 9 return envelopes. 24 LB white wove paper creates a professional look and feel from out of the box all the way to your destination.