4.0x Magnification Dental Loupes, Prismatic Keplerian Style Nickel Alloy Frame, 40mm Depth of Field+ 65mm Field of View+ 420mm Working Distance Loupe, Flip-Up Flexible Optical Glass Loupe Dentistry 4x magnification power, Keplerian Prismatic type binocular loupe with Nickel Alloy Frame Generous depth of field, extends the natural accommodation capability of the human eye Adjustable nose bridgeaccommodates any pupil distance, adjustableinter-pupillary distance Flip-up design and provides much more power and perfect for detailed operations such as root canals Extra wide field of view, combined withextra deep focus range,40mmDepth of Field, 65mm Field of View,420mmWorking Distance