Instrument for surgery

An end tool of a surgical instrument, comprising:

• a first jaw and a second jaw configured to rotate independently;
• a J11 pulley coupled to the first jaw and configured to be rotate around a first axis formed at an end tool hub;
• a J16 pulley formed at one side of the J11 pulley and configured to rotate around a second axis formed at one side of the first axis;
• a J12 pulley and a J14 pulley formed at one side of the J16 pulley, and configured to rotate around a third axis formed at a predetermined angle with the first axis and formed at one side of the end tool hub;
• a J21 pulley coupled to the second jaw and configured to rotate around an axis that is substantially identical to or parallel to the first axis;
• a J26 pulley formed at one side of the J21 pulley and configured to rotate around an axis that is substantially identical to or parallel to the second axis;
• and
• a J22 pulley and a J24 pulley formed at one side of the J26 pulley and configured to rotate around an axis that is substantially identical to or parallel to the third axis,
• wherein, based on a first plane perpendicular to the first axis and passing between the J11 pulley and the J21 pulley,
• two strands of a first jaw wire coupled to the J11 pulley contact one side from among an upper side and a lower side of the J12 pulley and J14 pulley, and
• two strands of a second jaw wire coupled to the J21 pulley contact one side from among the upper side and the lower side of the J22 pulley and J24 pulley, which is different from the one side from among the upper side and the lower side of the J12 pulley and J14 pulley.