Square Drive Professional Incorporates 'click' sound and 'snap' feel to indicate when torque setting has been reached. Sliding switch on the ratchet head for instant direction reversal (except model 300 and 330, which has a push through square drive). Setting lock to prevent accidental adjustment of the torque setting. Scale located within handle Nm/lbf.ft graduated (kgf.m or ibf.in scale also available, supplied to order). Accuracy to 4%. Supplied in sturdy blow moulded box for protection. On request 'P' Type wrenches can be set, marked with the setting and certified for production line applications requiring a sealed torque setting. Only if a pre-set torque value has been requested will the tool be supplied with a Declaration of Conformance. All Norbar torque wrenches are designed and manufactured to exceed the following national and international standards: BS6703: 1988, ISO 6789-2:2017 & U.S.A.GGG-W-00686-C (GSA-FSS).