Head Mounted Design: The head-mounted hands-free magnifier is an ergonomic spectacle frame, which can effectively prevent the magnifier from falling and reduce the pressure on the bridge of the nose. It is light and does not slip off, ensuring firm wear and reducing fatigue during long-term use. You can also free your hands and focus on the object you want to observe. Interchangeable Lens: There are 8 groups of interchangeable lenses in the package of our head-mounted magnifying glass: 2.5x / 4x / 6x / 8x / 10x / 15x / 20x / 25x, which can meet your needs for close work Kind of demand. It is recommended to choose a lens barrel with appropriate magnification according to the size of the object to be observed. The magnification can be quickly interchanged and placed in the corresponding lens storage box to keep it tidy. Single Observation: We required using only ONE eye loupe of the double-eye loupe glasses to view the object, because when using two glasses at the same time, the focus will fail. You can use the two lens barrels alternately to eliminate visual fatigue and effectively improve your work.Attention: This magnifying glass is suitable for close-range work, please stay closer to the target observation object. Detachable: The bracket and headband are interchangeable, both can be worn firmly and reduce fatigue during long-term use. And the adjustable magnifying glass bracket can be flipped up and down, you can flip to the desired position to ensure that the eyeball is in the middle position, you can see the details more clearly. Before use, it is recommended that you can flip the front lens up to use a SINGLE lens.