Polycarbonate Tubing, 1" ID x 1 1/4" OD x 1/8" Wall, Clear Color 24" L: Industrial Plastic Tubing: Amazon.com: Industrial & Scientific
1/2 Inch Diameter Clear PVC Schedule 40 Pipe [Pipe ID 0.602 inch, OD 0.840 inch] (Bluish tint), Choose Your Length (5 Inches to 8 Feet) (Selected Length: 18 Inches)
Amazon.com: MECCANIXITY PVC Rigid Round Pipe 12mm ID 16mm OD 200mm Clear High Transparency for Water Pipe, Aquarium, Fish Tank : Industrial & Scientific
uxcell PVC Hose Tube, 19mm(0.74") ID x 24mm(0.94") OD 3 Meter 9.8ft Clear Vinyl Tubing, Plastic Flexible Water Pipe - - Amazon.com