510 Basic Iris - shorter still and adjusts over the wider range 0.5 - 3.0 mm
- the fixed seat iris works with individually pin-located tempered spring steel leaves
- aim point precisely maintained throughout the wider range of
adjustment by introducing a new system of aperture control operated by
varying the pressure of a steel tube against the central aim point -
guaranteeing a perfect circle
- light reflection kept to a minimum by use of matt finishes internally and externally
- unique Gehmann patent not found in other irises
- Thread is male M9.5