Pure sine wave inverter for off-grid solar system 12V/24V-220V 200W, 300W, 500W Pure Sine Wave Inverter STI series STI series is a sine wave power frequency inverter which can convert 12V or 24V DC to 220V AC 50Hz based on full digital and intelligent design. It features high reliability, high efficiency, concise outline, small volume, full protection functions, easy installation and operation. ...