The microtube’s distal end contains a bevel and side window. The beveled end "scoops-up" the broken instrument into its lumen, and its side window potentially receives the head of the obstruction. The screw wedge is passed through the proximal end of the microtube and, upon contacting the broken instrument, is turned CCW to mechanically engage the obstruction. When engaged, the obstruction is removed by rotating the microtube and screw wedge assembly out of the canal. Note the black and red screw wedges may be interchanged between each microtube which, at times, improves mechanics.