4-1/8" x 9-1/2" ( 4.125" x 9.5" ), Flip-Stik Regular Envelope, No Window, Western Sulphite, White Sulphite Paper, Vellum Finish, Side Seam, Flap Down, Pres-Stik, Blue Inside Tint, 500 Qty / Box, 2500 Qty / Ctn, 7 lbs. per Box