Gehmann #522 Front sight Iris Foresight w/out Crossbar Crosshair 18 or 22mm

Gehmann #522 Foresight iris

Infinitely adjustable
Ring thickness of the iris: 1.5mm
Ring only

522A adjustable from 2.4 - 4.4mm
522B adjustable from 4.0 - 6.0mm
522C adjustable from 2.9 - 4.9mm
522D adjustable from 5.0 - 7.5mm
Available in 18mm and 22mm