original and intact "new old stock" vintage american industrial c. 1920's steam valve stem bonnet salvaged from the boylston factory, chicago, il. the diminutive valve component would likely have been used in pressure regulators or pumps. the bonnet is comprised of cast iron with a brushed metal finish sealed with a clear coat lacquer. ideal as a display stand. fabricated by the boylston steam specialties co., il. measures 4 1/2 x 5 inches.