Standard Left Window – Window measures 1 1/8" x 4 1/2", positioned 7/8" from the left and 1/2" from the bottom, ideal for displaying pre-printed addresses. Classic #10 Size – Measures 4 1/8" x 9 1/2", the most commonly used business envelope size. Made in USA Confidential Security Tint – Interior printed pattern ensures sensitive information stays private during mailing. Durable 24lb White Wove – Sturdy paper resists tearing while maintaining a professional appearance. Moisture-Seal Gummed Flap – Traditional gummed closure provides a secure, reliable seal. Perfect for Businesses – Ideal for invoices, statements, checks, letters, and other office correspondence. Made in USA