The DFS0403R1561P020 from Zhejiang Jiakang Electronics is a Band Pass Filter with Frequency 1.551 to 1.571 GHz, Bandwidth 20 MHz, Center Frequency 1561 MHz, Insertion Loss 1 to 2 dB, Rejection 20 to 45 dB. Tags: Surface Mount. More details for DFS0403R1561P020 can be seen below.