The SiMS21R8/1R2-8D3 from Sainty-Tech Communications Limited is a Band Pass Filter with Frequency 21.2 to 22.4 GHz, Center Frequency 21.8 GHz, Insertion Loss 3.5 dB, Rejection 30 dB @20.3GHz&23.2GHz, 40 dB @19.8GHz&23.3GHz, 55 dB @DC~19GHz, 50 dB @24~32GHz, Upper Rejection 30 to 50 dB. Tags: Surface Mount, Cavity Filter. More details for SiMS21R8/1R2-8D3 can be seen below.