JAM PAPER Plastic Envelopes with Button & String Tie Closure - #10 Business Booklet - 5 1/4 x 10 - Red - 12/pack Color: Red Size: #10 (5.25 x 10 inches) Quantity: 12 per pack Our envelopes have a 1-inch expansion and feature a button and string closure designed to keep contents inside secure and organized Booklet #10 envelopes are the best way to organize your important papers, memos, projects, presentations, letters, and forms at home, the office, school, or on the go