Dual  reading scale  0 - 150ft.lbs  0 - 21m.kg. Best quality carbon steel. A good quality wrench with deflecting beam which inidicates torque on engraved scales.  The head has two 1/2" square drive locations on which a conventional socket of the required size can be fixed.  Scales graduate in both directions together with the double head, allowing the wrench to be easily read, whether being used over or under the fixings.