An electromechanical surgical system (10), comprising: a surgical instrument (100) that includes an instrument housing (102) defining a connecting part (108a) for selectively connecting with a shaft assembly (200), in which the surgical instrument has at least one rotating actuating member (118, 120, 122)； an end effector (400) configured to perform at least one function； and wherein the shaft assembly (200) is arranged to selectively interconnect the final effector (400) and the surgical device, in which the shaft assembly includes: a transmission housing (212) configured and adapted for selective connection to the connecting part (108a) of the surgical device and to be in operative communication with each of the at least one rotating actuating member (118, 120, 122) of the surgical device； an outer tubular body (210) having a proximal end (210a) supported by the transmission housing (212) and a distal end (210b) configured and adapted for its operative connection with the final effector (400)； an articulated neck assembly (230) interconnecting the tubular body (210) and a distal neck housing (236) comprised in the articulated neck assembly, in which the articulated neck assembly is configured to allow articulation outside the axis of the distal neck housing, in which the distal neck housing (236) interconnects a rotating actuating member (118, 120, 122) of the surgical instrument and a rotating receiving member (426) supported in the effector (400 ) end, in which the distal neck housing (236) includes a first end that can be connected to the rotating actuating member (118, 120, 122) of the surgical instrument and a second end that can be connected to the member (426) for receiving rotation of the final effector, wherein the distal neck casing (236) transmits a rotation of the rotating actuating member (118, 120, 122) of the surgical instrument to the rotating receiving member (426) of the final effector (400), wherein the distal neck housing (236) includes: at lea
