The BT4128 from INSTOCK Wireless Components is a Bias Tee with Frequency 10 to 4000 MHz, Max. Voltage 100 V, Max Current 1.5 A, Power 100 W, Insertion Loss 0.3 to 0.35 dB. Tags: Module with Connector, SMA, SMA - Female. More details for BT4128 can be seen below.