#10 Double Window Envelope - Blue Inside Tint - 24# White (4 1/8 x 9 1/2) - Double Window Series (Pkg of 100) A Quantity of 100 - #10 Double Window Envelope - Security Lined - 24# White Wove Paper Great for mailing invoices, statements, checks, letters, and more. - Top Wdo: 1 1/8 x 3 1/2, 3/8 from Left, 2 5/16 from bottom. Btm Wdo: 1 x 4, 3/8 from left, 3/4 from bottom. Note: The window locations can vary by 1/16 of an inch during the manufacturing process. This envelope may be sourced from any one of a number of top brands. Ships via Priority Mail