PSA means Pressure Sensitive Adhesive. They're self-adhesive sanding discs that rapidly and simply attach into a sanding machine. Offered in possibly cloth backing or paper backing with fabric getting used for hefty responsibility grinding and paper becoming a far more cost-effective and light-weight option for lighter sanding/finishing. You should note, https://www.facebook.com/permalink.php?story_fbid=pfbid02qy5RYwv9mRHSFYwncPbxRsdtEco9SbCfbnAheuxAs1drJAu8uwWJX23DPnghtnrcl&id=61560512640678&__cft__[0]=AZVECecDFdwp9WLUavNF_NqeonZijvhHENjG_jRXUkIllE4rZhtTITKA7DzRPFiCrjUDolI-fwlu6SlV1ZocBH1QSpBAIUaos6uRPM6WHrpvENB0AOmAeSmmRHi6IjeC61mKPY3WIjRCHG32rBXdK1FipgkW4L5HdVUDxJaypqhtJVInTZ65MpOC8-z_2ill-etiShQwY4Hz3k3jBopbGrBj&__tn__=%2CO%2CP-R