This product is a relay-type high accuracy household voltage stabilizer and transformer. Ideal power source for voltage regulation for modern household electrical appliances. Designed to transform 220 volts into 110 volts up to 5000 watts. It can safely be used with a wide range of electrical equipment, including home appliances, tools, computer equipment, etc. Ventilated design for continuous use. It is applicable for areas with large fluctuations of electric network voltages. Input voltage: AC120V-250V 50HZ/60HZ with 3 sec. delay function with low or over - voltage protection. Output voltage is rated at 110V +-8%. The manufacturer recommends you purchase a transformer that is 25% higher then the wattage you need. You should know that you will never damage your appliance with a higher voltage transformer, however if you buy one that is nor powerful enough, it will not work. Remember to leave at least a 100% slack for the transformer. Some items, such as laser printers and power tools spike when you turn them on. For these types of situations you need to buy a transformer that is at least 3 times the items capacity.