Product Detail Optimal Mounting:Three 2.5" HDD or SSDs can be mounted perfectly in the 3.5" drive bay of your case. Wide range compatibility with fan's thickness: Choice to mount up to 38mm thickness fan. Compatible with the PC case, which has fixed mounting rails . The "Scythe Bay Rafter 2.5 or 3.5 hard drive conversion to 5.25 bay" is best product for you. We recommended Scythe Bay Rafter 2.5 or 3.5 hard drive conversion to 5.25 bay