Battery Pack connects directly to the headband allowing complete freedom of movement. Powerful and lightweight our single watt LED at 5250 degrees Kelvin produces a bright, white, cool, shadow free light, with 50,000 hours of life! Operates using convenient AA batteries - choose alkaline or rechargeable. Compared with Welch Allyn we're not only brighter at 130+ Lumens versus only 20 Lumens - we are priced $180 less! You'll not only feel the difference in the pocket, you'll see it!