Weller spn series soldering irons with led illumination weller sp40nkuk a high performance 40w mains powered soldering iron with the latest led technology that illuminates the work area while solderingthe front housing is ergonomically designed encouraging the hand to naturally gravitate to the triangular area this provides a more stable and effective grip enhanced by the soft grip non slip handle design that helps relax the hand during extended useideal for soldering printed circuit