A revolutionary feature of this product is the wide range of outputs that are available. The 50w, 100w, 200w and 400w are all compatible with the gold Infrared lamp unit. The lamp is simple to use, much like any other heating product - think of it like a light bulb without the light. It should always be used with a dimming thermostat and the correct wattage for the size of the enclosure and amount of heat you wish to produce should be selected. The 400w unit is ideal to use at a distance of 30-36 inch from lamp to basking area for a basking temprature of 82-95°F. At the distance of 30-36 inch you will get a light spread diameter of 48-55 inch Ø. Infrared allows natural basking behaviour, as if the animal were in its own native enviroment. Infrared penetrates deep into the skin, activating many different chemical reactions and raising the core body temerature which aids optimal digestion.