Features With LED magnifying optical glass, enlarge the object to 20-40 times its original size. Extremely bright LED lights, brighten the the items you are examining even in the darkness. Widely used in microelectronics, precision machinery, jewelry, watch, archaeology, biological anatomypathology, school teaching and other fields. Designed for anyone else who is looking to read or observe small details of text or parts. This HD optical lens with high transmittance, brings a clear image and a distortion-free increase. Specification: Item Type: Magnifier Material: ABS+Optical Lens Magnification: 20-40X Lens Diameter: 14mm/ 0.6in Battery: 3 x LR43 Button Battery Package List: 1 x Magnifier  1 x Instruction 2 x Glass Slide 1 x Base Package List 1 x Magnifier 1 x Instruction 2 x Glass Slide 1 x Base