501MC Gehmann rearsight iris, silver/blue

Iris 0.5 - 3.0mm
In an attractive, anti-reflective matt silver and blue finish
Laser engraved indications
Steel threaded connection - which for example enables the use of a diopter
5 external push-fit rubber rings which attach to the knurled ring in: Red, yellow, green, blue and black
Designed to provide an illusory optical effect which ensures perfect eye alignment
An extremely simple and inexpensive idea that gives an exceptional improvement