2. Main technical indexes
(1). Range of PD adjustments:
PD of both eyes: 48-80mm
Left or right PD: 24-40mm
Minimum calibration value: 1mm

(2). Frame adjustable length : 35mm

(3). Nose pad adjustable angles :360°

(4). Axial calibration on each disc:
Left disc: 120.0.135.
Right disc: 45.180.60.
Axial xalibration increase along the lens frame axis counter clockwise ,and the calibration distance is 5..
(5). Inner diameter of lens frame:φ32.5mm
(6). Number of lens which can be inserted into left or right lens frame simultaneously:4 pieces
(7). Degree of lens rotating around optical axis in the lens frame::360°

(8). Nonparallelism between lens'optical axis and lens frame's geometric axis:≤ 2.5.
(9). Non-concentricity between lens'optical center and lens frame geometric center:≤0.5mm
(10). Displacement of lens in relation to position of lens frame geometric center:≤0.3mm
(11). Range of nose pad adjustment:length:0-14mm;Angle:0.30.
(12). Range of lett or right lens frame leg'length adjustment:98~135mm
(13). Maximum interval bewteen left and right lens frame legs:200mm