#10 Square Flap Envelopes (4 1/8 x 9 1/2) - Ruby Red (50 Qty) | Perfect for Checks, Invoices, Letterhead, Letters, Statements | EX4860-18-50 Size: #10 Square Flap Envelopes / 4 1/8 in x 9 1/2 in / 4.125" x 9.5" / 105mm x 241mm Quantity: Pack of 50 Color: Ruby Red USES: Checks, Invoices, Letterhead, Personal Letters, Statements, Bills, Flyers. Applications: Business Mailings, Direct Mail, Corporate Mailings, Financial Mailings, Personal Mail. Printable on off-set printing presses and some home printers.