Specifications:

1. Method of Measurement: cornea reflection light coincidence method
2. Range of Measurement: 44 to 83 MM (both eyes), 22 to 41.5 MM (each eye)
3. Graduations: 0.5MM
4. Range of Focusing Point: 30 to infinity
5. Power Suppy: 6V DC (Lr03 Batteries * 4)