Durable nylon washers for standard carbon dioxide fittings. Fits common CO2 couplings with CGA 320 thread type (13/16in thread diameter) such as draft beer and hydroponics applications. The washer is reusable and long-lasting featuring a raised edge to hold securely in place for leak-free connections. Pack of 9. Color varies. Dimensions: Outside Diameter: 0.75in (19mm) Inside Diameter: 0.25in (6.4mm) Thickness: 0.13in (3.2mm)