Unfortunately like all other reputable filter manufacturers they have shifted to China for manufacturing of their products. We really don't know how filters perform. We install and remove them in time. Unless they fall apart we can only conclude they work. When we take into account on past products coming from China and their reliability we cringe when we see Made in China on the label. I stick with UFI. So far no made in China on those labels. MANN and other European mostly Germany are my first priorities. That's my choices.