The WVR-866.2B-4.6M01 from Wevercomm is a Band Stop Filter with Stopband Frequency 863.9 to 868.5 MHz, Bandwidth 4.6 MHz, Insertion Loss 1 dB, Rejection 50 dB, Power 1 W. Tags: Module with Connectors, Cavity Filter, Notch Filter. More details for WVR-866.2B-4.6M01 can be seen below.