Lighter-than-air construction makes this comfortable magnifier perfect for long wear. Supplied with 3 easy to change lenses; 1.75x, 2.25x and 2.75x; lenses are made in USA of optical grade acrylic with precise optics, coated lenses reduce scratches, mars and abrasions, increased better light transmission creates a brighter image, ratchet knob strap adjustment, padded comfort headband.