The QB-904 from Spectrum Control is a RF Amplifier with Frequency 2 to 6 GHz, Gain 30 to 40 dB, Gain Flatness ±2 dB, Noise Figure 6.5 to 8 dB, Saturated Power 3.981 to 5.012 W. Tags: Module with Connectors, Driver Amplifier. More details for QB-904 can be seen below.