The SiMF2R8/R4-6D3 from Sainty-Tech Communications Limited is a Band Pass Filter with Frequency 2.6 to 3 GHz, Center Frequency 2.8 GHz, Insertion Loss 2.5 dB, Rejection 30 dB @2.25GHz&3.3GHz, 40 dB @2.1GHz&3.4GHz, 60 dB @DC~1.9GHz, 60 dB @3.5~6.5GHz, Upper Rejection 30 to 60 dB. Tags: Surface Mount, Cavity Filter. More details for SiMF2R8/R4-6D3 can be seen below.