I have installed these fans 11/2 years ago. I had then built into a 5 piece BigTower. These 5 80 fans I have interconnected so that a connection on the board all have the same speed. Just as it is advertised. Works great. I order the noise a fully insulated housing, so I need a lot of fans for the purpose of air circulation. I bought the fan for less than 3 per piece and they run today still like the first day. It has become even no down or louder. My PC runs all day. I am something of enthusiasm. Because I would have never thought of this money something decent to get.