... spot: The brightness of the tip is =1000 LXMagnification of lens: 2.5 xDiameter of ear-specula: 2.5mm, 4.0mmInsufflation ... ±4D, ±6D, ±8D, ±10D, ±15D, ±20D.5. Aperture wheel: red-free filter, Large spot, small spot, hemispot.Technical Specification:Name of aperture ... ±1D, ±2D, ±3D, ±4D, ±6D, ±8D, ±10D, ±15D, ±20DAperture: red-free filter, Large spot, small spot, hemispotRated voltage: AA alkaline or Ni ...