Designed to significantly reduce power supply fan noise Fits most standard & mini-tower cases. Anodized aluminum construction with pre-installed 7mm noise dampening pads Complete with instructions The unit comes in 2 pieces of anodized aluminum with 7mm acoustic absorption pads pre-installed. The power supply silencer can greatly reduce the noise coming from the fan in the power supply & doesnÃt impede the flow of hot air coming from it. Power Supply Silencer is a must have to turn your PC to the true silent computer.