a palm wrench includes a c - shaped body and a driving head . the driving head is pivotably and rotatably located within the body . the body has an opening , and the driving head has two function ends on two sides thereof . the driving head is pivotably connected to the body by two pivots which extend through the body and are connected to the driving head . the driving head can be rotated with respect to the body , and the user can grapes the body to rotate the driving head to output torque .