The HE551 from Sainty-Tech Communications Limited is a RF Amplifier with Frequency 900 to 1300 MHz, Gain 28 to 30 dB, Gain Flatness ±1.0 dB, Noise Figure 1 dB, Output Power 11 to 11.5 dBm. Tags: Low Noise Amplifier. More details for HE551 can be seen below.