This adapter allows you to use any sizeLuer Lock needlefor any of our injectors. It is two-part assembly that steps down the barrel nut from the injector to a Luer Lock "hub" that will accept any standard Luer Lock needle. This way, you can buy a smaller gauge needle from an outside source. Our current (one-piece)mini needleis 3" 14g, and does not need this adapter assembly. This product is made in the USA.