A surgical device comprises an elongate shaft defining a longitudinal axis. The shaft comprises a distal end and a proximal end. An arm medially deflect able and comprises a mating feature. An elongate pin is positioned medially relative the arm. The elongate pin is axially slideable relative the arm between a locked position preventing medial deflection of the arm and an unlocked position allowing medial deflection of the arm. An energy based surgical end effector is selectively attachable and detachable to the mating feature of the arm. The end effector may include a torque arm to engage the elongate shaft.
