Parameter of the bolster-laryngoscope: No.DescriptionTechnique parameter Limited tolerance Remarks1Field of view ≥60° 2Angle of view 0°,12° ±10°3Zoom (work length 40mm) ≥1× 4Definition(work length 40mm) ≥7.02Lp/mm 5Depth of Field 2mm-150mm No upper limit6luminance >5000Lx