Diopter: 4Magnification (w/ 3.5-Diopter Lens): 2.88xWorking Distance (W/ 3.5-Diopter Lens): 5.5"Magnification (w/ 5-Diopter Lens): 3.25xWorking Distance (w/ 5-Diopter Lens): 4.3"Lens Diameter: 2"Lens Diameter (Overall w/ Gasket): 2.5"