<p>The surgical tool comprises a longitudinally extending waveguide (1) defining a longitudinal axis (2). A first jaw member (1b) is connected at a distal end of the waveguide (1). A longitudinally extending carrier tube (3) is rotatable about the waveguide (1) and a second jaw member (6) is pivotably mounted to a distal end of the carrier tube (3). An outer shroud (7) includes a guide lobe (9) bearing on a rearward face of the second jaw member. Rotation of the carrier tube (3) causes pivoting of the second jaw member (6) into and out of operative relationship with the first jaw member (1b).</p>
