The WVR-835B-20M01 from Wevercomm is a Band Stop Filter with Stopband Frequency 825 to 845 MHz, Bandwidth 20 MHz, Insertion Loss 2 dB, Rejection 40 dB Min @ 825MHz to 845MHz, VSWR 1.50:1. Tags: Module with Connectors, Cavity Filter, Notch Filter. More details for WVR-835B-20M01 can be seen below.