Black Telescoping Drafting Tube (Pack of 2) - 4" Outside/3-3/4" Inside Diameter, Expands 30-1/4" to 52", Durable Protection with Shoulder Strap - Ideal for Posters, Blueprints, ArtBlack Plastic Telescoping Document Poster Tube with 4" diameter that expands from 30 1 4" up to 52" is ideal for artists, architects, and poster collectors Poster Tube is made of a very rigid plastic to protect contents from bending or creasing in transit. Tube is also water and light resistant, it protects materials against fading from exposure to sun light Now includes an Extra Long Shoulder Strap that is comfortable for use even when the tube is