Upak 4"x6" White Poly Mailer Envelopes, Easy Peel, 100 Count Unsurpassed Water & Tear Resistance Heavy Duty Polyethylene 100 Count - 4" Wide x 6" Long White outer surface/Grey inner lining (Flat Mailer, Not a Bubble Mailer) Pressure sensitive self seal Light Weight, Time Saving, & 100% recyclable