The HE381B from Sainty-Tech Communications Limited is a RF Amplifier with Frequency 20 to 500 MHz, Gain 11 to 12 dB, Gain Flatness ±0.5 dB, Noise Figure 2.4 dB, Output Power 12 to 12.5 dBm. Tags: Power Amplifier. More details for HE381B can be seen below.