The BR52-10-B/B from Quantic PMI (Planar Monolithics) is a Band Stop Filter with Stopband Frequency 47.5 to 56.5 MHz, Insertion Loss 1.5 dB, Rejection -30dBc @ 47.6 TO 55.6MHz, VSWR 2.1:1. Tags: Module with Connectors. More details for BR52-10-B/B can be seen below.