16 NA-AV4 silicone anti-vibration mounts for up to 4 fans Reduces structure-borne noises by effectively decoupling the fans from the PC case Flat case-side end for clean exterior look 5 defined, numbered pawls for standard open corner fans (pawl 1) and 10, 14, 15, 20 or 25mm thick fans with closed corners (pawls 2 to 5) Compatible with all Noctua fans and many third-party fans, 6-year manufacturer’s warranty