APS Racing USA Billet Aluminum Cap & Weld-In Bung Assemblies
http://www.apsracingusa.com APS-Racing Cap and Bung assembly can be welded to any suitable tank or plate. It drops into a 1½ inch hole that can be welded on power steering tanks, radiator overflow tanks, valve covers, rear ends, filler neck plates, and other locations to replenish fluid, or as an inspection port. Cap and bung are made of 6061-T6 Aluminum. Includes O-Ring for leak free sealing. Made in the USA.