The SiMF3R1/R8-7D2 from Sainty-Tech Communications Limited is a Band Pass Filter with Frequency 2.7 to 3.5 GHz, Center Frequency 3.1 GHz, Insertion Loss 1.9 dB, Rejection 30 dB @2.3GHz&3.9GHz, 40 dB @2.15GHz&4GHz, 60 dB @DC~1.7GHz, 60 dB @5~7.5GHz, Upper Rejection 30 to 60 dB. Tags: Surface Mount, Cavity Filter. More details for SiMF3R1/R8-7D2 can be seen below.