Specification:
1.Effective measurement range:
Binocular pupillary distance: 45～82 mm
Left or right pupillary distance: 22.5～41 mm
2.Step: ∞, 2m, 1m, 65cm, 50cm, 40cm,35cm,30cm
3.Indication error：≤0.5mm
4. Asymmetrical error: ≤0.5mm
5.Rounding error：≤0.5mm
6.Distance of target：30 cm ～∞
7.Power source：5# AA battery/2*1.5V
8.Size and weight: 221mm(L)×166mm(W)×63mm(H) 0.64kg

Specification:
Range of measurement:
48 to 77 mm(Both eyes)
24 to 38.5mm(Each eyes)
Graduations:0.5mm
Range of focusing point:30 to infinity
Powe supply:4.5V DC(Lr.7 batteries X3)