The MLFI-42004 from Micro Lambda Wireless, Inc. is a Tunable Filter with Tunable Frequency 2 to 4 GHz, Bandwidth 30 MHz, Rejection 80 dB, Input Power 10 dBm(Limiting), Insertion Loss 5 dB. Tags: Module with Connectors, YIG Filter. More details for MLFI-42004 can be seen below.