For Air Conditioners, Freezers, Ice Makers, Washing Machines or any Large Appliances. Protect your appliance from High or Low voltage by interrupting the current flow.Once the voltage returns to normal, the SAFETY CYCLE will light up for 4 minutes before it turns to green.After this period, the green light will turn on which will allow the current to flow.Please note that the function of this product is similar to a fuse, where a sufficient power surge will disrupt its function in order to protect the appliance plugged in. The product can only do so once, so after it has protected the appliance from a surge it is spent and will no longer continue to function.