The MRF1550N from NXP Semiconductors is a RF Transistor with Frequency 135 to 175 MHz, Gain 14.5 dB at 14.5 MHz, Power 50 W, P1dB 50 W, Supply Voltage 12.5 V. More details for MRF1550N can be seen below.
450 Watt, 50 Volt, 3.1 to 3.5 GHz, GaN RF IMFET
15 Watt, 50 Volt, DC to 4 GHz, GaN RF Transistor
15W, 300 MHz to 1.215 GHz, GaN RF Input-Matched Transistor
You can now find similar products from multiple companies on everything RF.