Box Dimension: 3.1"x 1.5"x 2.5", inner size: 2.5" x 2.1" x 1.5" Made from 32ect-B kraft corrugated, high quality, super strong yet light-weight to save on postage and packaging, perfect for shipping small, lightweight, fragile items Assembles in seconds without tape, glue or staples. The cardboard boxes are easy to fold in seconds.No tape is needed when in use, and can be unfolded when not in use This durable boxes can support up to 65 pounds,There are three layers of cardboard on the left and right sides of the mailer boxes to support the weight and prevent the corrugated mailer boxes from deforming Great for cosmetics, jewellery and other small item.