A surgical instrument comprising: (a) a body having a proximal end and a distal end, with a handle positioned at the proximal end; (b) a removable insert (200, 300) including a measurement indicator; (c) an end effector positioned at the distal end of the body, the end effector having a distal interior surface facing the proximal end of the body, the end effector being configured to receive the removable insert; and (d) an actuation feature in communication with the end effector and the removable insert when the removable insert is received in the end effector, the actuation feature being configured to advance the removable insert distally toward the distal interior surface of the end effector; wherein the measurement indicator of the removable insert is configured to determine thickness of tissue positioned between the removable insert and the distal interior surface of the end effector; wherein the removable insert is configured to be advanced a preset distance by the actuation feature, from a preset retracted position in which it is not in contact with tissue, to a preset advanced position in which it is in contact with tissue; wherein the measurement indicator comprises a mechanical gauge assembly and a measurement display scale, wherein the mechanical gauge assembly is in communication with the measurement display scale, wherein the removable insert comprises a proximal end and a distal end and an insert axis disposed therebetween, wherein the mechanical gauge assembly comprises a pressure reception component disposed perpendicular to the insert axis, and wherein the measurement display scale is oriented perpendicular to the pressure reception component; wherein the mechanical gauge assembly further comprises: (i) a horizontal linkage coupled to the pressure reception component and extending parallel to the measurement display scale, and (ii) a pivotable linkage having a first end coupled to the horizontal linkage and a second end slidably coupled to the measurement display scale at another end via a first pin, wherein the pivotable linkage is configured to pivot about a point between the first end and the second end; wherein the mechanical gauge assembly of the removable insert is configured to determine tissue thickness of tissue positioned between the removable insert and the distal interior surface of the end effector when the removable insert is in its preset advanced position, and wherein the position of the first pin relative to the measurement display scale displays the determined tissue thickness. (a) a body having a proximal end and a distal end, with a handle positioned at the proximal end; (b) a removable insert (200, 300) including a measurement indicator; (c) an end effector positioned at the distal end of the body, the end effector having a distal interior surface facing the proximal end of the body, the end effector being configured to receive the removable insert; and (d) an actuation feature in communication with the end effector and the removable insert when the removable insert is received in the end effector, the actuation feature being configured to advance the removable insert distally toward the distal interior surface of the end effector; (i) a horizontal linkage coupled to the pressure reception component and extending parallel to the measurement display scale, and (ii) a pivotable linkage having a first end coupled to the horizontal linkage and a second end slidably coupled to the measurement display scale at another end via a first pin,