Description: Main Function: * This kind of product is designed for the electrical appliances with voltage of AC 110/220V used in the area of AC 220/240V voltage and this kind of product is designed for the electrical appliances with voltage or AC 220/240V used in the area of AC 110/120V voltage. They are for use with all electronic and electrical equipment(up to rated wattage). The maximum power rating must not be exceeded by the appliance connected to the transformer. No warranty will be honored if transformer is burned out by exceeding the rating. To convert 110 volts to 220 volts: Make sure the appliance to be plugged in uses fewer watts than the transformer's rating. Insert the voltage tap plug (located on the rear of the transformer) into the pair of holes marked "110". Plug the transformer's power cord into a source of 110 volts. 220 volts will be available at the front panel outlet marked "220" volts when the power switch is turned on. To convert 220 volts to 110 volts: Make sure the appliance to be plugged in uses fewer watts than the transformer's rating. Insert the voltage tap plug (located on the rear of the transformer) into the pair of holes corresponding to the local voltage standard (200, 220, or 230 volts). Check carefully to be sure no error has been made. Plug the transformer's power cord into a source of 200, 220 or 230 volts. 110 volts will be available at the front-panel outlet marked "110" volts when the power switch is turned on. Note: To prevent damage and possible fire hazards, the fuse should be replaced with a slow-blow fuse (MDL) of the same ampere rating as the original if the fuse continues to blow, the transformer and/or the appliance connected to it may need repair. Package Included:1Transformer Note:The power of our transformer must be 2.5 times larger than the buyer's appliance to be used normally.