A stylus includes a stylus member including a first housing defining a first receptacle; a stylus body assembly slidably and non-rotatably accommodated in the first receptacle. The stylus body assembly including a first threaded hole, and a pen member including a second housing defining a second receptacle, a pen assembly slidably and non-rotatably accommodated in the second receptacle. The pen assembly defining a second threaded hole therethrough; and a shaft including a first threaded portion engaging with the first threaded hole and a second threaded portion engaging with the second threaded hole so rotation of the shaft relative to the first housing and the second housing causes the stylus body assembly to extend into or retract from the first housing and the second housing respectively.