Trial Frame Progressive Trial Frame Optic Vision Machine Optical Instrument Eyeglass Processing Equipment Eye Shop Material Aluminum magnesium Package Includes 1xTrial Frame Size 52-70mm/2.04-2.75Inches Pupil distance range 50; 52; 54; 56; 58; 60; 62; 64; 66; 68; 70mm Axis scale 360° on the right. The marking interval 5° Effective internal aperture of frame Φ38mm The number of lenses that can be inserted into the left and right frames 3 Rotation degree of optical axis of lens in inner ring of frame 360 ° The nonparallelism between the optical axis of the lens and the geometric axis of the frame ≤2.5 The difference between the optical center and the geometric center of the lens ≤0.5mm Displacement of the lens relative to the geometric center of the frame ≤0.3mm Displacement of the lens relative to the geometric center of the frame ≤0.3mm Adjustable length range of the left and right frame leg 125~155mm Model Trial Lens Frame Packing size 18*26*5cm Gross weight 0.8/5pcs Warranty 18month