Hi Stan, I have a Centaur with the typical noisy fan..I have replaced the 811's with 572B's and wondered if the 310 fan you show on your lists is the quiet replacement for this noisy one I have. Thanks for any info. Gary N5BI _____________________________________________________________ Click to receive credit card help and get out of debt fast http://track.juno.com/s/lc?u=http://tagline.untd.us/fc/Ioyw6iifRlPsRcWqCFxAoQTpoas7Uc7BH6a8X7e95N4NKzoLmPxSvx/