The Sun Switch is a light activated mains electricity switch. When the Sun Switch is in the light, the power will be switched on and when it is in the dark, the power will be switched off. The difference between the on and off levels has been adjusted so that the unit does not flicker at the triggering point nor will it switch on and off due to minor variations in brightness. Essentially, the unit detects day and night and can therefore switch things on that are required during daylight hours. The range of items that can be switched is only limited by a maximum load of 600 watts and the imagination. Most uses will include switching those things that act like an artificial sun, that is heaters and lights. One of the major advantages of the Sun Switch is that natural day/night cycle is duplicated, including the seasonal variations of long day length summers and short day length winters.