The preset invention includes a circuit board wired to connect at least one common terminal and a plurality of signal terminals to form multiple instruction switches and an annular click member. Each of the instruction switches has an elastic contact element built with a return force. The circuit board has a plurality of displacement portions. The annular click member has actuating portions corresponding to and engageable with the displacement portions such that the annular click member is movable up and down relative to the circuit board to form a normal position and an instruction generating position. When the annular click member receives a force and is moved to the instruction generating position, a contact depresses the elastic contact element to store the return force When the force is released from the annular click member it is pushed by the return force of the elastic contact element to the normal position.