I have a RadioShack soldering iron and the tip on it was in poor condition making it difficult to use. After some research I found out that this model should fit my soldering iron. Indeed, and now I've been able to use it multiple times, and it's much nicer to have a tip that doesn't have a missing piece. This nib is a good size although a little oversized for finer work. I have to do this, or maybe my skills aren't what they should be.