With one twist of the wrist these black plastic tubes telescope from a fully closed 24" length to a fully extended 40" length. Innovative twist lock design enables you to lock the tube at ¾" increments. An ideal solution for safely storing and transporting blueprints, drawings, maps, posters and more, these tubes feature a 3" inside diameter and fully adjustable shoulder strap. Screw cap closes tightly and includes a clear plastic cover that lets you easily label and relabel each tube’s contents.