Replaces / Supersedes: 4295, 429536, 662766470567, Pan Pads, CDC Anti Clog FT/C Units, CDC Anti Clog FT/CS, SPPFTCS Units and more. PanPads® by Nu-Calgon utilize a quaternary-based biocide, formulated in an encased plastic housing which in turn is sealed ultrasonically to an absorbant white filter pad.