GrovTec makes by far the best sling swivels available, and I say this as a professional gunsmith. They are American made, as opposed to that other familiar “uncle” brand, which seems so homey, but is really Chinese. The knobs on these are steel; the “uncle” ones are plastic and always eventually break. GrovTec cost a little more, but you get what you pay for, and they’re well worth it! They’re the only brand I use or recommend.