The SiMF4R2/R2-5D4 from Sainty-Tech Communications Limited is a Band Pass Filter with Frequency 4.15 to 4.35 GHz, Center Frequency 4.25 GHz, Insertion Loss 4 dB, Rejection 30 dB @3.8GHz&4.7GHz, 40 dB @3.7GHz&4.85GHz, 60 dB @DC~3.4GHz, 60 dB @5.1~11.4GHz, Upper Rejection 30 to 60 dB. Tags: Surface Mount, Cavity Filter. More details for SiMF4R2/R2-5D4 can be seen below.