Range of measurement：

Binocular pupillary distance:    

48～77 mm

Left or right pupillary distance:

24～38.5 mm

Indication error：            

≤0.5 mm

Rounding error：             

 ≤0.5 mm

Distance of target：          

35cm～∞

Power source： Voltage：      

DC 4.5V,3 pieces AA battery

Time for automatic shut-off： 

About 1 minute after stopping operation, or turn it off manually.

Size：                        

233mm(L)×165mm(W)×70mm(H)

Weight：                      

0.68kg