It's a style of box used in the eCommerce space for shipping products safely and is the outer box that has the shipping label placed on it. It is made of a thicker paperboard (cardboard) corrugated flute sheet of 1/8" thickness. The colour of the corrugate sheet can be white or brown on either side and can have a coated finish or an uncoated and natural finish. They are simple and easy to assemble and require less storage space since they are supplied in flat sheet bundles. Mailer boxes provide a secure yet fun unboxing experience when your recipient opens the package as the product is visible as soon as the outer box is opened.