Help to eliminate dB of PC noise by reducing the noise generated by fan vibrations. Tool free install. * The special composition of rubber will absorb vibrations and reduce fan noise. It can help enhance the longevity of your hard drive. * Suitable to closed chassis fans with thickness 25mm. * Suitable to open chassis fans with thickness 4mm * Rubber foot screws complies to 3.5" or 2.5" HDD.