Amazon.com: 2" Aluminum Square Tube 1/4" Wall x 24" Long 6061-T6 Mill Finish : Industrial & Scientific
Amazon.com: Aluminum Round Tubing - 1/2" OD x .050" x 48" Long : Industrial & Scientific
K & S 1115 Round Aluminum Tube, 5/16" OD x 0.014" Wall x 36" Long, 4 Pieces, Made in The USA: Metal Industrial Wall Tubing: Amazon.com: Industrial & Scientific