The KNP820S57A from KeyLink Microwave is a RF Amplifier with Frequency 806 to 825 MHz, Gain 57 dB, Output Power Limit 56.99 dBm, Output Power Limit 500.03 W, AC Voltage 100 to 260 VAC, 50/60Hz V. Tags: Power Amplifier. More details for KNP820S57A can be seen below.