These tubes have a 3" inside diameter and unique design that permits telescoping from fully closed 27" length to fully extended 50" length. Durable, water-resistant plastic with a “twist-off” screw cap. Friction lock at any length by twisting tube. Tubes are designed for anything that can be rolled. Perfect for protecting charts, drawings, maps, blueprints, posters, etc. against creases, bends, tears and folds. Adjustable length shoulder strap provides convenient portability. Strap and mounting can be removed for storage. Packaged 12/box. Black only.