These revolutionary new lights are ideal for the cabinet grower or for those with heat considerations. They may be used on their own or as supplemental lighting for bigger grow rooms. They can be hung in any position just 175mm from the foliage. Based on similar technology to the energy saving bulbs now in most households, as you'll see from the picture, these are a high intensity version. Like the home bulbs, they consume less watts per lumen and the reduced heat output results in longer life. Also like the home bulbs, they take a few minutes to reach full intensity and suffer a noticeable drop in lumens as they get older. We'd recommend you change these bulbs once every 18 months.