FILTERS FOR COMMUNICATIONS EQUIPMENT RESIN MOLDED, MULTI-ELEMENT CFJ/CFS/CFL455kHz The following lines of filters are high performance devices that achieve ultimate stopband attenuation through the use of multiple piezoelectric elements connected in ladder form. A few of the recommended applications for these filters include high class receivers, SSB communications equipment, pocket pagers and mobile radios. CFJ455K 11 Ceramic Elements CFS455 15 Element Filters CFL455 9 Eleme.