HVM-4Set as out our HVM-4 Premium Binocular Headband Magnifier,however the set is a Visor style comes with 4 Lens set 1.5x, 2x, 2.5x, 3.5x optical quality glass lenses. (Optional eye loupe available for $4.00) The Headband on this magnifier is fully adjustable to fit any size quickly and easily, visor is also adjustable +/- 60 degrees either way making it easy to flip up and out of the way of the line of sight. The HVM-4Set has premium features including 4 lenses with magnification from 1.5x-3.5x, lightweight durable impact resistant visor shell and an aluminum alloy headband pivot mechanism as well as scratch resistant glass prismatic lenses, more suitable for the industrial environments. The 3.5x glass prismatic lens gives you an close working distance of 4" for most repetitive applications and hands free magnified view. 3.5x is the highest magnification for binocular (both eyes) magnified view, anything beyond 3.5x and the focal length is too close to see with both eyes. Can be worn over eyeglasses and many safety glasses. Other lens magnifications available for purchase for the HVM-3 and HVM-4. Our standard size lenses will also fit many other headband magnifiers including OptiVISOR® Brand.