The Norbar TTi Wrenches are accurate upto ±3%, which exceeds all international standards for torque wrenches. Every wrench comes with a traceable calibration certificate. Quick and light adjustment over the entire scale can be quickly achieved with minimal effort in approximately 10 complete turns (exact number varies by model) and they have a micrometer scale for simple and error free setting. All models have an adjustment lock to prevent accidental adjustment of the set torque. The ratchets have a narrow engagement angle of 5º on the TTi50 and 6º on all other models, allowing easy positioning of the tool in the tight confines of today’s vehicles and machines. They also have a comfortable, durable handle that is constructed using 2 materials: a base material for strength overlaid with a soft feel grip for comfort and slip resistance. The handle and lens resist chemicals in common usage in the automotive, aviation and industrial environments. TTi 20 Torque Wrench 1/4in Square Drive 4-20Nm specification detailed below. NOR13830