... -MH batteriesElectrical Safety Standard: GB9706.1 internal power sourceThe direct ophthalmoscope is used for examining the interior structures of the eye ... and comfortable operation.3. Suitable for small pupil.4. 19 lenses from 0D to ±20D: 0D, ±1D, ±2D, ±3D, ±4D, ±6D ... -MH batteriesElectrical Safety Standard: GB9706.1, internal power equipment Diagnostic Set