The main advantage of power savers is not that they provide a backup system in times of low current, but that it protects the household appliances. It is known that a sudden rise in the power can destroy the electrical appliance.Please ensure you PowerVolt Energy Saver follow all the instructions contained in the message. These estimates are based on normal circumstances and are not a guarantee of delivery times. The shipping time mentioned above refers to the estimated time of business days that the shipment will take after an order has been shipped. The total delivery time is calculated from the time your order is placed until the time it is delivered to you.