1/2" ID (13 mm) Copper Crush Washers Brake Hose Spacer Flat M13 fit on 13mm Bolt Pack of 20 : Amazon.ca: Musical Instruments, Stage & Studio
Copper Gasket for 1/2 in. ISO Parallel (Gauge) Thread (RG) Fitting | Spare Parts and Accessories | Tube Fittings and Adapters | Fittings | All Products | Swagelok