The 4000NF39A6550 from Johanson Technology is a Band Pass Filter with Frequency 3.2 to 4.8 GHz, Bandwidth 1600 MHz, Insertion Loss 2.2 dB, Rejection 14 dB, Power 0.5 W. Tags: Surface Mount, Ceramic, Ceramic Filter. More details for 4000NF39A6550 can be seen below.