The GGYoptics hard tube mirror is the using up study lens transmission. Optical fiber passes on the light straight bamboo mirror. Its characteristic is forms image the nature to assume the high. Easy to operate to be possible widely to use in profession and so on rolling stock. Automobile, machinery, petrification not damages the examination. Technical parameter: Working length:175mm750mm Work outer diameter: Diameter:2mm -- 9mm Angle of view:60 Regards approaches: View to90 degree 70 degree 30 degree 0 degree Best work distance:7mm 100m Deepest:5mm --infinitude