551 Gehmann iris, twin polariser and 1.5x diopter

Iris 0.5 - 3.0mm
Two polarisation filters:
- 1. ring eliminates reflections and controls white around target
- 2. ring (with stainless lugs) controls light through the sight and enables varying degrees of brightness
10 - 90 % light absorption via the twin polarisers
Can be used as an iris only - or with one, or both, polarisers
1.5x diopter with -4.5 to +4.5 correction
Detachable optical system for use of thread adaptor such as 577
Easy clean instructions included