Security Envelope Designed To Match With Your 1099 From, From Quickbooks Or Similar Accounting Software. Your 1099 Copy B And Copy C Forms Will Slide In Perfectly 24# White Wove Confidential Security Tinted Double-Window Envelope,No Worry About Personal Tax Identical Information Showing Through The Envelope Windows Envelope Size: 5 3/4 X 8 3/4 Two Clear Windows To Reveal The Return Address And The Recipients Address Set Of 25 Tax Envelope, Irs Approved