Features: *Provides a suitable and comfortable wearing experience, can be adjusted *PD Adjustment Range: Binocular PD: 48 ~ 80 mm; Left or Right PD: 24 ~ 40 mm; Minimum Scale Value: 1 mm. *Lenses can be rotated 360 in the frame. *Number of lenses that can be inserted in the left or right frame at the same time. *Axial scale increases counterclockwise along the frame with a 5 scale distance. Specifications: Color:Black +Silver Size:15.50*6.00*3.50cm Range of PD adjustments:PD of both eyes: 48 ~ 80mm;left or right PD: 24 ~ 40mm;minimum graduated value: 1mm Dividing disc axial graduation: Left dividing disc:120~0~135 Right dividing disc:45~180~60 Inner diameter of lens frame:32.5mm. Degree of lens rotating around optical ax is in the lens frame:360 Nonparallelism between lens'optical ax is and lens frame's geometric a xis:2.5 Non-concentricity between lens'optical center and lens frame geometric center:0.5mm Displacement of lens in relation to position of lens frame geometric center:0.3mm Range of nose rest adjustment: Length:0 ~ 14mm; angle:0 ~ 30 Range of left or right lens frame leg's length adjustment:98 ~ 135mm. Maximum interval between left and right lens frame legs:200mm Material: lightweight metal or plastic Package Included: 1pcsTrial Frame Note: 1. The real color of the item may be slightly different from the pictures shown on website caused by many factors such as brightness of your monitor and light brightness. 2. Please allow slight manual measurement deviation for the data.