The Weller DX113HM 0051315099 is a 2.49mm Desoldering Tip with threadless fixture system for use with the DSX 80 and DXV 80 desoldering irons. The X-series 1.9mm nozzle tip, when nozzle is inserted into the head and locked into place by applying a 1/4 turn. This feature allows the nozzles to be quickly and easily exchanged and also improves the rate of thermal transfer from the head to the nozzle.