The RSF-1842.500-75000-1109-TR-NS4 from Raltron is a Band Pass Filter with Frequency 1805 to 1880 MHz, Bandwidth 75 MHz, Center Frequency 1842.5 MHz, Insertion Loss 2.0 to 3 dB, Rejection 37 to 23 dB. Tags: Surface Mount, RF SAW Filter. More details for RSF-1842.500-75000-1109-TR-NS4 can be seen below.