200 lb. test strength corrugated mailers are shipped flat and bundled. Adjust to a size that fits your materials. Scored at 1/2" or 5/8" intervals. Prevents product damage. For books, catalogs, photos and other printed materials Shipped flat and bundled. Some taping required to assemble mailer. Order in multiples of 100, same item number Ships prepaid by UPS from IL factory in 24 hours. Allow normal transit time from factory to final destination.