Amazon.com: MECCANIXITY Plastic Pipe Rigid Polycarbonate Round Tube Clear 0.7"(18mm) ID 0.8"(20mm) OD 14" (350mm) High Impact for Lighting, Models, Water Plumbing, Pack of 5 : Industrial & Scientific
CLEAR ACRYLIC PERSPEX TUBE 16MM 18MM 20MM 22MM 24MM & 25MM, 250MM OR 500MM LONG | eBay
China Plastic Detachable Test Tube Racks For 13mm 15mm 18mm Manufacturer and Supplier | Huida
Transparent Acrylic Hard Tube Pipe Od 8mm 10mm 12mm 14mm 16mm 18mm 20mm Pmma Pc Water Cooling Rigid Tube 50cm Length - Fluid Diy Cooling & Accessories - AliExpress
Uxcell 14mm ID 18mm OD 6.6ft PVC Clear Vinyl Tubing Plastic Pipe Air Water Hose - Walmart.com
Plastic Pipe Rigid Tube Clear 0.7"(18mm) ID 0.8"(20mm) OD 17" (425mm), 3pcs - - 36760239