The GS66502B from GaN Systems is a GaN Power Transistor with Gate Threshold Voltage 1.1 to 2.6 V, Drain Source Voltage 650 V, Drain Source Resistance 200 to 516 milli-ohm, Continous Drain Current 6.3 to 7.5 A, Pulsed Drain Current 15 A. Tags: Die. More details for GS66502B can be seen below.