EKWB EK-HD PETG Tube 10/12mm 500mm (2pcs) Only use 10/12mm PETG tube with 10/12mm hard tubing fittings! Cannot be used with Imperial sized fittings PETG tube is perfect for hard tubing beginners who prefer stronger and more forgiveable hard tubing EK recommends using EK-HD Tube D.Y.I. Kit 10&12mm For Bending This Acrylic Tube Inner diameter: 10mm Outer diameter: 12mm