After trying different contact tips, I found these to be the best ones for my welding projects .THEY are durable and deliver consistent performance. The tips fit seamlessly into my welding gun and I didn't have any issues. They come in a variety of sizes, which is useful for different welding applications. The only downside is that they are a bit pricey, but it's worth the investment for their quality. Overall, i highly recommend these contact tips for any welding enthusiast or professional..