ZOOM C Mount Lens is mainly used in the following fields: Machine vision microscopic inspection Industrial testing, especially electronic component testing scientific research Education industry. 1X-130X Zoom C-mount Lens: Work distance: 40mm-170mm Zoom ratios: 1: 17 Magnification Power by 0.1-1.3X (about 1 - 130X on the display) view field of Max multiple: 8mmx4.5mm view field of Min multiple: 40mmx33mm / 1X-150X Zoom C-mount Lens(50 ring): Working distance: 50mm-1000mm zoom ratios: 1: 15 Magnification Power by 0.15-2X (about 1 - 150X on the display) view field of Max multiple: 4.2mmx2.4mm view field of Min multiple: 130mmx70mm / 1X-180X Zoom C-mount Lens: Working distance: 100-150mm Zoom ratios: 1: 6.5 Magnification Power by 0.7-4.5X(about 1 - 180X on the display) view field of Max multiple: 2.8mmx1.5mm view field of Min multiple: 25mmx14mm / 50X Zoom high distance lens(42 rings): Eyepiece lense: 0.5X Tips: The product may be updated constantly, The Actual Product May Have Slight Differences Or Color Differences the color and appearance may be changed, please don't mind. And take a consideration before place the order if you have request for color or appearance. Material: Metal colour: Black Package Contents: 1 x 130X short Lens / 1 x 50X high distance lens(42 rings) / 1 x 150X high distance lens(50 rings) / 1 x 180X long lens Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.