The SiMF8R4/R1-4E3 from Sainty-Tech Communications Limited is a Band Pass Filter with Frequency 8.38 to 8.42 GHz, Center Frequency 8.4 GHz, Insertion Loss 3.5 dB, Rejection 25 dB @8.1GHz&8.8GHz, 40 dB @7.9GHz&9GHz, 60 dB @DC~6.5GHz, 50 dB @10~13.5GHz, Upper Rejection 25 to 50 dB. Tags: Surface Mount, Cavity Filter. More details for SiMF8R4/R1-4E3 can be seen below.