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 +SilverSize:15.50*6.00*3.50cmRange of PD adjustments:PD of both eyes: 48 ~ 80mm;left or right PD: 24 ~ 40mm;minimum graduated value: 1mmDividing disc axial graduation:Left dividing disc:120~0~135Right dividing disc:45~180~60Inner diameter of lens frame:32.5mm.Degree of lens rotating around optical ax is in the lens frame:360Nonparallelism between lens'optical ax is and lens frame's geometric a xis:2.5Non-concentricity between lens'optical center and lens frame geometric center:0.5mmDisplacement of lens in relation to position of lens frame geometric center:0.3mmRange of nose rest adjustment: Length:0 ~ 14mm; angle:0 ~ 30Range of left or right lens frame leg's length adjustment:98 ~ 135mm.Maximum interval between left and right lens frame legs:200mmMaterial: lightweight metal or plasticPackage Included:1pcsTrial FrameNote: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.