The WRCD20-1828-1830-1855-1857-40 from Wainwright Instruments is a Band Stop Filter with Stopband Frequency 1.83 to 1.855 GHz, Bandwidth 25 MHz, Insertion Loss 2 to 3.5 dB, Rejection 40 dB, VSWR 1.50:1. Tags: Module with Connectors, Cavity Filter. More details for WRCD20-1828-1830-1855-1857-40 can be seen below.