The Model 5556 from Netcom is a Tunable Filter with Frequency 1.5 to 4 MHz, Bandwidth 0.075 to 0.175 MHz, Input Power 1 W, Peak Power 2 W, Insertion Loss 2.5 to 3.8 dB. Tags: Drop-In (Thru-Hole), Digitally Controlled. More details for Model 5556 can be seen below.