4" x 42" Kraft Telescoping Mailing Tubes. Telescoping tubes provide a custom fit to your mailing. Telescoping tubes expand in length to accommodate different size documents with the same tube. Heavy-duty 1/8" double wall, spiral wound construction. Tubes have a 6" flush-joint cap. To seal simply adjust to desired length and seal with tape or shipping label. Available in case quantities. Case of 15.