Magnification (1+F/4): 3.0xEquivalent Power F (D): 8.0Lens Diameter: 48.0mmImage Vergence: -4.0DEffective Focal Length: 25.45mmField of View on Page: 80.0mm8270/01 (3x) Magnifier & ChargerPart No:8270/01 Technical SpecificationsMagnification (1+F/4): 3.0x Equivalent Power F (D): 8.0 Lens Diameter: 48.0mm Image Vergence: -4.0D Effective Focal Length: 25.45mm Field of View on Page: 80.0mm