23mm lens holder allows a prescription lens to be fitted eye-side of your rearsightFor all other manufacturers irises and our own earlier versions that didn’t have the ability to remove the front attachment threadMount your prescription lens in the lens holder which may be slid off the rail for easier assemblyReposition the lens holder on the rail as required and lock it in placePositioning of the assembly on your rearsight is easily set as the attachment boss has radial adjustment and is simply secured with the allen screw located in the front bodyLens holder for Gehmann irisesContact us at 70822-33324, if the product is in pre-order status.