LX-7 Donegan OptiVISOR with lightweight acrylic lens is a hands-free, headband binocular magnifier that has 2.75x lightweight acrylic lens vs the normal glass, the acrylic lenses are ground and polished into prismatic lenses for quality and clarity, and provides a focal length working distance of 6" other lenses are available in varied magnification which provide specific magnification power (X) at specific focal lengths, or distance from object. The Donegan OptiVISOR is considered by many to be the finest headband magnifier available and has been proudly made in the USA for many decades and is highly durable and widely used in industrial and commercial applications.