Designed to prevent equipment from becoming overloaded.The most common use for the On Switcher is to prevent your lighting timer from melting and short-circuiting. Many growers who have used high wattage lighting systems with cheap timers have found that the timers fail prematurely. In fact, in many cases you will see that over time the plug and outlet on the timer begin to turn brown, and in some cases even melt. Another common use is when you have an expensive grow room controller that is able to control several lights. Since your controller cant handle thousands of watts flowing through it, and you probably dont have a 100A circuit breaker in your home, the On Switcher enables you control several lighting systems by plugging all of the sense cords into the controller and then plugging the On Switchers into outlets on separate circuits.The On Switcher uses your inexpensive timer to simply close the connection between the wall outlet and the lighting system or any other appliance instead of having the electricity flow through the timer into the appliance. Its just like plugging the light directly into the wall outlet, but you still have the benefit of being able to time the light. With such a tiny amount of electricity flowing through the timer, not only with the timer last longer, you will be taking a huge step towards safeguarding your appliance and your grow room. Think of it this way - no one wants to come home to be greeted by the fire department - its the cheapest insurance you will ever buy.To operate, you start by simply plugging the On Switcher into the outlet you wish to use for your lighting system or other device. Next, plug the lighting system into the outlet on the front of the On Switcher. Then, plug your existing economy timer into any wall outlet and set the timing schedule you desire. Finally, plug the sense cord from the On Switcher into the timer. Whenever the timer turns on it will complete the circuit between the wall outlet, On Switc