This is a great magnifier for industrial purpose circuit board and printing industry medical science?gardening coins and stamp education geography house living and offices. The automatically light-up and goes off LED is perfect for seeing clearly in the dark. - Magnification: 45X - Lens diameter: 21mm - Great magnifier for industrial purmpose circuit board and printing industry medical science gardening coins and stamp education geography house living and offices - With bright white LED illumination (3*LR1130 Battery included) - Pull the magnifier out and white light lite-up - Push the magnifier back and the light goes off