Amazon.com: MECCANIXITY PVC Rigid Round Pipe 33.5mm ID 40mm OD 0.3 m Clear High Transparency for Water Pipe, Aquarium, Fish Tank : Industrial & Scientific
uxcell 3pcs Clear Rigid PVC Pipe 25/32"(20mm) ID x 13/16"(21mm) x 1.5ft, 0.02" Wall Round Tube Tubing: Amazon.com: Industrial & Scientific
MECCANIXITY Plastic Pipe Rigid Polycarbonate Round Tube Clear 2.8"(71mm) ID 3"(75mm) OD 17" (425mm) High Impact for Lighting, Models, Water Plumbing - Amazon.com