Columbian #10 Grip-Seal Envelopes, 4-1/8" x 9-1/2", White, 500 Per Box (CO147) Convenient and secure self-sealing Grip-Seal closure; simply peel off release strip and press down for a quick, secure seal Envelope is ideal for all business, professional and personal correspondence Premium 24 lb. white wove stock; #10; 4-1/8" x 9-1/2"; 500 envelopes per box; made in USA