Sunwin Digital Pd Meters Optical Pd Meter Digital Pupilometer Pupillary Distance Pd/vd Meter PDs

Specification:
PD Meter is a precision optical instrument used to measure distance between pupils in the process of optometry for spectacles
Effective range of measurement:
Binocular pupillary distance: 45-82mm
Left or right pupillary distance: 22.5-41mm
Absolute value of indicated error: ≤0.5 mm
Absolute value of asymmetrical error: ≤0.5 mm
Absolute value of rounding error: ≤0.5 mm
Focus range: 30cm to infinity
Power source:
Voltage: DC 3V
Specification: 5#AA battery (the batteries are not included)
Quantity: 2 pieces
Time for automatic shut-off: About 1 minute after stopping operation, or turn it off manually
Size: 221mm(L) x 164mm(W) x 63mm(H)
Weight: 0.66kg
What is in box ?
1 X Digital PD Meter
1 x English User Manual