This is a replacement soldering tip for the Weller WLC100 soldering iron. It is a flat type of soldering tip, measuring 0.125" (3.17mm) wide. Replacing the tip is a breeze --- simply unscrew the currently attached tip with a flat-head screwdriver, slip the replacement tip in, and screw it into place.
The flat Weller tip has been pre-tinned with a lead-free alloy.
Note: This is the tip that ships with the WLC100 Soldering Station.