WXSF 120 Feed Unit The WXSF 120 feed unit combines a high-performance 120W soldering iron function with an automatic solder wire feed for precise and efficient manual soldering processes. This unit is ideal for working on circuit boards, wiring harnesses, connectors, or switches and improves soldering quality through a precise and preset solder supply. The adhesive-coated inner sides of the feed tube prevent the flux from sticking and reduce maintenance costs. Additionally, the device offers a start-stop/standby function as well as the choice between pulse or timer mode.