Headband Magnifier LED Light HeadMounted Head Loupe for Reading Embroidery Tattoo Condition: Item Type: Headband MagnifierFive Groups of Replacement Lenses for Both Eyes: 1x 1.5x 2x 2.5x 3.5x Three Groups of Replacement Lenses for One Eye: 5x 8x 20x Lighting Source: 2 x white LED lights Battery: 3 x AAA battery (not included)Size: As shows in picture Scope of Application: It can be used for beauty, eyelash extension, tattoo, reading, newspaper reading, painting, handicrafts, textiles, flowers, bonsai viewing, watch repair, jewelry identification, antique appreciation, etc. The three lens multiples of a single eye can produce six different multiples: 5x 8x 13x 20x 25x 28x Five different multiples of double spectacle lenses can be combined with each other to produce 11 different multiples: Magnification Corresponding focal length  1.0x  250-350mm  1.5x  200-300mm  2.0x  175-275mm  2.5x  150-250mm  3.0x  135-235mm  3.5x  80-120mm  4.0x  60-110mm  4.5x  50-100mm  5.0x  45-90mm  5.5x  40-80mm  6.5x  35-75mm