Combined Lens Slot Design & More Choices of Magnification: The headset magnifier is equipped with 5 interchangeable lenses and one small round auxiliary lens, which are made of shatterproof crystal clear optivisor acrylic lens. You can combine these 5 lens and round lens (8x) or only use a single lens to get 23 kinds of magnification to meet different requirements: 1x, 1.5x, 2x, 2.5x, 3x, 3.5x, 4x, 4.5x, 5x, 5.5x, 6x, 8x, 9x, 9.5x, 10x, 10.5x, 11x, 11.5x, 12x, 12.5x, 13x, 13.5x, 14x.