Quantic PMI Model Number BPF-3D55G4D4G-850M-SM-2 is a Bandpass Filter center frequency 3.975 with a 3.4 dB bandwidth of 3.55 to 4.4 GHz. The filter is built in a surface mount package measuring 1.75" x 0.35" x 0.32" ideal for use in integrated modules.