Plastic Courier Mailing Bag 1). 50 or 100 PCS/ PP Poly Bag, 10/20 Packs(1000pcs)/Carton; 2). Customized Outer Packaging for wholesale based on your requirement; 3). Exactly meet the standard of US Market/Amazon Warehousing. poly mailer/custom design poly mailer/factory direct mail bag/waterproof plastic envelopes