uxcell PVC Clear Vinyl Tubing, 16mm(5/8") x 19mm(3/4") Plastic Tube Flexible Water Pipe 3.3ft - - Amazon.com
Amazon.com: METALLIXITY 6063 Aluminum Tube (16mm OD x 7mm ID x 300mm L) 3Pcs, Aluminum Round Tubing - for Home Furnishing, Machinery, DIY Handicraft : Industrial & Scientific