These backplates adapt conventional velcro backed discs for use on regular power tools. Flexfoam™ brand backplates are cushioned to allow full contact between the workpiece and the diamond disc and mount on a 5/8 x 11 threaded shank. Plain backplates are rigid and have a 1/4" dia. mounting mandrel. Flexfoam™ brand inserts can be added to the plain backplates for a cushioned effect. Tech-Lok™ brand holders are used with Tech-Lok™ brand diamond discs.