the internal structure is made of alloy steel and the shell is made of abs resin, resistant to rust and corrosion. high precision torque screwdrivers are certified and tested. with clear scale for controlled torque tightening. torque screwdriver wrench 1-6nm ideal for controlled release bolts.the torque value can be preset and there is an audible alarm prompt, which brings more convenience. when the clamping torque of the fastener reaches the preset torque value, it can automatically send a "click" signal, accompanied by an obvious vibration of the hand, indicating that the work is completed. the special design of the ergonomic handle prevents the hand from slipping off the tool during use. 36-piece set: 1/4-inch torque screwdriver, 30-piece bit: pho, ph1, ph2, ph3; 3,4,10,5,6,8; 2.2.5,3,4,5,6,8; 3/32",7/64",5/32",3/16"; t6,t8,t10,t15,t15,t10. 20,t 5,t30,t40;1/4"ad; 1/4" hex socket adapter; 5pcs cr-v hex sockets 4-8mm usage: work on bicycle, motorcycle, automotive, precision mechanics.top quality for professional and commercial use.