Environmentally Responsible Lamps High light output.;Energy efficient alternative to T12 HO lamps.;ALTO lamp technology means better for the environment. Philips leads the industry with the lowest level mercury technology. Reducing the mercury level (source reduction) during the manufacturing phase is essential to creating products that are less harmful to the environment. Available in 44, 55, and 65 watts, 3000, 3500, and 4100 color temperatures. Ideal for outdoor, cooler applications.