Unsurpassed Water & Tear Resistance - Superior side seams combined with Heavy Duty polyethylene make these High Quality envelopes highly resistant to water, punctures, and tears • Pressure sensitive self seal - Easy packing, tamper-evident, and super secure closure • Light Weight & Time Saving - Lower shipping costs combined with faster shipment preparation equal big savings over other packaging option ❤️ UPS/USPS/Fedex shipping envelope approved #shippingkit #polymailer