SainSmart LCR-T4 Transistor Tester Diode Triode Capacitance ESR Meter MOS/PNP/NPN L/C/R For 12864 LCD liquid crystal display with backlight, backlight is usually yellow-green color. Cascading power supply for 9 v battery. If the power supply for a long time, can use two of lithium battery 8.4 v battery power supply.