Test Item Component Tester Transistor GM328 DIY Kits Diode Capacitance ESR Meter Tool Kit Capacity Tester The GM328A test components and shows the test results on the clear digital LCD screen. This tester automatically detects if a NPN/PNP transistor, FET, diode, dual diode, thyristor or SCR is connected and has an automatic identification of the pinout of the components