#10 Regular Envelopes (4 1/8 x 9 1/2) - 24lb. Bright White - Return Service Requested (50 Qty.) | Perfect for Checks, Invoices, Letterhead, Letters, Statements | 43687-RETSER-50 Size: #10 Regular Envelopes 4 1/8 in x 9 1/2 in / 4.125 x 9.5 / 104.775mm x 241.3mm Quantity: Pack of 50 Color: 24lb. Bright White - Return Service Requested USES: Checks, Invoices, Letterhead, Personal Letters, Statements, Bills, Flyers. Applications: Business Mailings, Direct Mail, Corporate Mailings, Financial Mailings, Personal Mail. Printable on off-set and digital printing presses and some home printers.