Head can be rotated 360 degrees, corrosion resistance, toughness, torque. Rotary switch, easy to use. Specification: 12-13-14-15-16-17-18-19mm 8-10-12-13-14-17-19-21mm NOTE: 1.Product are taken in kind, but because of lighting problems, pictures may have a slight chromatism. 2.Due to the difference between different monitors, the picture may not reflect the actual color of theitem. Please consider this before the purchase. 3.Please allow slight deviation for the measurement data.