mailing tube
noun[C]
ukusCOMMUNICATIONS
alonghollowcylinder, usually made ofpaperorcardboard, used tocontainandprotectlargedocumentssentbymail:
Eachkitincludessuppliestohelpstudentscreateoriginalbillboarddesigns, such as amailingtubetosubmitcompletedentries.