Round 16 Od Ss Pipe, 6 meter, Thickness: .26-1.2 mm Thk
Amazon.com: 6 Pcs 1 inch Vsttar Seal Flexible Tank Adapter (Bulkhead). Pipe ID - 1" (25mm) Pipe OD - 1.315" (33mm) Hole saw Size- 1.75" (44.4mm) Up to 3/8" Wall Thickness (9mm) :
PVC Pipe Sizes: A Guide to Understanding OD Sizes
PVC Pipe Round Rigid Plastic Tube 4mm ID 6mm OD 500mm White 2 Pack | eBay