Bell system tool to transpose wires, $100 postpaid. Incuse marked on side: BELL SYSTEM / PATENTED MAY 14, 1918 / DEC.1.1925 (embossed on top swivel part) (arc) DROP FORGED / [W in diamond] IN U.S.A. (embossed on other side of swivel part) VULCAN / No.4 (embossed on top loop) DROP FORGED IN U.S.A. (embossed on opposite side) VULCAN No. 24. The main piece is about 10" x 8" x 1.5".