Mid century vintage, 8'' round glass fresnel lens for studio task lights or theater lamps, like Mole-Richardson Solar Spots or Bardwell-McAllister lights. This lens is marked "Silver-litecraft Corp, Passaic, New Jersey", "Pyrex" and is marked 8-3/8 inches. It measure 8-3/8" in diameter (across) and about 3/8" thick overall. This lens is in excellent condition.