The HE581 from Sainty-Tech Communications Limited is a RF Amplifier with Frequency 800 to 2500 MHz, Gain 19 to 22 dB, Gain Flatness ±0.75 dB, Noise Figure 3 dB, Output Power 13 to 13.5 dBm. Tags: Power Amplifier. More details for HE581 can be seen below.