Aeroquip FCM2404 Tank Welding Bung (AN 871), Aluminum, For Size -08 Fitting Expertly designed and manufactured for exceptionally high quality Add to a tank to create a location where you can attach a fitting; connects to Male AN Flare with hex and O-Ring 1.75 inch diameter, .68 inch thick, and the opening is size -08 Manufactured from high-quality aluminum to be durable and light weight 1 year limited manufacturer's warranty