An end effector comprising a first jaw member having a first tissue contacting surface, a second jaw member having a second tissue contacting surface opposing the first tissue contacting surface of the first jaw member, the first and second jaw members moveable relative to one another between an open position and a clamped position and a detection assembly disposed within the first or second jaw members configured to detect an attribute of tissue between the first and second jaw members, wherein the detection assembly is configured to prevent a function of the end effector based on the detected attribute of tissue.
