The HEM391A from Sainty-Tech Communications Limited is a RF Amplifier with Frequency 20 to 700 MHz, Gain 15 to 16 dB, Gain Flatness ±0.5 dB, Noise Figure 3 dB, Output Power 17 to 17.5 dBm. Tags: Power Amplifier. More details for HEM391A can be seen below.