DM-3 This Dome Magnifier has a 3" Inch diameter (medium size) and 4x magnification, the 3 inch is our most popular size due to its high magnification and very useful field of view. Dome Magnifiers are one of the easiest magnifier types to use, just place the magnifier on a flat surface for 4x magnification ideal for magnifying newspapers, charts, paperwork, books, financial and accounting statements and documents. Simply place the Dome magnifier on the surface and glide across to easily view with 4x magnification, the bottom of dome magnifiers is slightly concave to prevent scratching. We use only optical grade acrylic to make our Dome Magnifiers. Comes with protective storage pouch.