This is a replacement needle for most of the Iwata / Mr Hobby Procon / Sparmax / Tamiya airbrushes with 0.4mm nozzle. If you encounter problem with your paint job, the most common issue is with the paint. But the needle comes in second. Make sure you have a straight and polished tip needle in your airbrush. Sometimes you can fix it with some hard work, but if once the tip of the needle was bent, it may also damage the nozzle. So you should purchase an replacement needle.