I found these porcelain suspension insulators in Wantagh, NY. On one side of the metal, it is stamped with the number "2852". Directly below that it says "10,000 LB". Above that, written on the porcelain disk, it says "Chance". Directly under that it says "1963". On the opposite side, the metal is stamped "Chance" and directly under that it says "Made In U.S.A."