Specifications: <br> 1. Torque limiting screwdrivers feature aluminum scale and tube to reduce weight and enhance durability. <br> 2. This torque screwdriver has three features when tightening fasteners: smooth, accurate, and consistent effects. When the torque achieves its maximum, the mechanism will automatically slip to prevent over-tightening. <br> 3. All models have an easy-release bit holder which securely retains bits or sockets during the operation. <br> 4. Clearly laser scale; each torque screwdriver with laser serial no. which can be traced easily. <br> 5. Spring-loaded locking collar locks the scale when the torque is setting. <br> 6. All torque screwdrivers are made of the best materials which can reach the exacting tolerance. <br> *MATERIALS <br> Bit holder：S45C <br> Hexagon Knob: Anodic treatment <br> Graduated ring & tube：aluminum <br> Grip: TPR <br> *MATERIALS <br> Bit holder：electroplating <br> Hexagon Knob: Anodic treatment (yellow) <br> Graduated ring & tube：Anodic treatment (black) <br> *HEATREATMENT <br> Bit holder：HRB 90~94 <br> Hexagon Knob: HRB 25~30 <br>