These super-soft silicone fan gaskets are designed to dramatically reduce the vibration from any PC or server case cooling fans. The 60 & 70mm gaskets are 1.5mm thick, & the larger sizes are 2.5mm thick. Included with each gasket are silicone washers & anti-vibration screws. These screws feature a thread design which prevents the shank touching the fan & vibrations being transmitted & amplified through to the chassis. These gaskets are suitable for the vast majority of case designs & fan combinations, as they fit standard fan mounting holes. Slightly lengthened (12mm thread) fan mounting screws are supplied with the fan gaskets & washers. These gaskets can be used with standard PC cooling fans, & not just with Acousti Fan™ quiet case fans. Note: Do not use these gaskets in very high temperature locations inside a PC/ Server such as attached to CPU or GPU heat sinks! ** Fitting instructions** 1. Fit the fan gasket onto the outside of the fan housing (it will stay on the fan) 2. Position the fan & gasket together against the inside of the case, so that the four mounting holes in the fan & gasket line up to the mounting holes in the case side 3. Locate the four silicone washers & screws, & fit the washers against the case side, each secured by a screw 4. Tighten the screws enough to very slightly compress the silicone rubber. Do not overtighten. ** Features** 1. Help to absorb the fan vibration 2. Help to seal the small gap between the fan & the casing/enclosure wall 3. Compatible with virtually all case cooling fans 4. Supplied with screws & silicone washers 5. Quick & very easy to fit