Experience top-tier performance with a fit unlike any headlamp you've experienced thanks to BioLite's award-winning 3D SlimFit Construction. With a front profile of only 10mm and weighing only 78 g, HeadLamp 425 sits flush on the forehead without worry of bounce or slippage. Moisture-wicking fabric keeps you cool and dry for any activity and the rechargeable battery means you can leave the alkalines behind.