This is a voltage regulator/stabilizer device. It is labeled AUTO STAC and its function is to stabilize the electrical voltage and protect devices from voltage fluctuations (high or low). Benefits: * Maintains stable electricity for sensitive devices. * Protects TVs, computers, receivers, or older devices from electricity fluctuations. * Switches between 110V and 220V depending on the available outlets. * Has a meter that shows the voltage level. It has 110V and 220V outlets. * Power button. * 5 Ampere protection fuse. * Approximate capacity written: 500VA, meaning it is suitable for light and medium devices, not for large appliances like air conditioners (price is indicative).