FN America is known for producing quality firearms. Those same guns are fed with the best magazines available, and these are as good as they get. This is a 10 round factory .40 S&W magazine for the new FN FNS polymer framed pistol. It will also fit the FN FNX pistol. The magazine has a steel body with a blued finish. No other option will feed as reliably as the original FN America.