Disclosed are a stator assembly and a torque assembly device. The movable plunger includes a cap configured to engage the knuckle at a locking position of the plunger for locking the knuckle in the closed position. The invention composition may be used for washing andor conditioning keratin materials, and especially the hair. The MFRP is configured to receive a floor request signal and to selectively grant floor control to a requesting user. In addition, the gate insulation layer is not exposed, thus protecting the gate insulation layer from being recessed.