These cap style magnifiers have a one size-fits-all velcro style closure to firmly but comfortably attach the magnifier to your head for hands free work. Cap style magnifiers have a fixed standard three dimensional lens and a fold-in fold-out snap action secondary lens. Perfect for working with fine gold, jewelry, examining ore specimens or any close up work where hands free magnification is required. The primary lens has a 1.8 X magnification, second lens brings the total magnification to 2.3 X, and an additional one inch round magnifier swings down to provide a total possible magnification of 3.7 X or 4.8 X . Weighs approx. Features a LED light powered by 4 AAA batteries. Weighs 7 ounces.