OTC Tools OTC 7401 Ratcheting Chain Wrench, 3" to 6-3/4". Head design permits turning in either direction without removing wrench from the work. Ratcheting action also makes it possible to regrip without removal. Handles parts of most any shape... round, square, hexagon, octagon. 19" handle with capacity of 3" to 6-3/4" O.D.