Excellent for shipping large orders, Qwith an expansion to accommodate overstuffing. It's good practice to keep a stock on hand, in the event that one is needed. Between the open end design and self-sealing closure, flexible poly mailers streamline the process to get deliveries out on time. Seam Type: Weld; Flap Type: Square; Trade Size: #5 1/4; Security Tinted: No.