New Programmable Band-Pass and Band-Reject (Notch) Filter Modules Click below for more information on each product Frequency Devices introduces the "NEW" 824BP, 828BP and 828BR Series of 2- and 4-pole pair programmable center frequency (fo) filter modules. Each 2" x 2" module is factory tuned to one of three factory set tuning ranges or an 8-bit custom range from 1 Hz to 25.6 kHz. Available "Q's" for band-pass modules are 1, 2, 5 or 10 and for band-reject modules 3 or 10.