I was trying to find the correct tip for the Weller SPG40 soldering iron that came with my WLC100 soldering station. If you are looking for a new tip for this model, choose this one. It's small enough to handle most hobbies. Changing attachments is a hassle (especially when they're hot), so I'm always looking for the perfect balance between small enough to be precise and big enough for general use. For me that is the advice. Buy three at once.