The Infinity Cap is designed to offer end users reliable protection and enable full use of their Night Vision Devices. Built out of durable 6061 T6 Aluminum, the Infinity Cap is ready to take abuse. Securing to the NVG objective lens via threads, the Infinity Cap will not run the risk of popping off and an o-ring keeps debris out. The Infinity Cap features a polycarbonate sacrificial lens to keep your NVG objective lens from being scratched or damaged as well. Additionally, the Infinity Cap offers huge levels of focal adjustment with the patent-pending click-stop™ technology. With the turn of the Infinity Cap Turret, you can adjust the from 23.5mm down to 1mm with a click-stop™ at 5.66mm which puts you right at infinite focus. This crucial stopping point allows users to quickly shift their iris to infinity via tactile feedback, allowing users to easily identify what's in front of them with full clarity. If lighting does not permit infinity focus, the user can gradually adjust open or open it all the way quickly if lighting conditions change rapidly. Our iris system gives you the perfect balance of adjustability and utility. Durable 6061 T6 Aluminum Housing Anodizing conforms to MIL-A-8625F Type II Class 1 and Class 2 Standard Securely mounts to the objective lens to avoid accidental removal Polycarbonate sacrificial lens for 92% light transmission O-ring for keeping debris out Adjustable Iris that goes from 1mm to 23.5mm Click-Stop™ technology allows you to quickly set the iris to infinity via a tactile “click” feedback Sacrificial lens holder can accept aftermarket accessories for pvs-14 style lens such as LIF or sacrificial lenses with an outside diameter not exceeding 32.4mm Made in Canada Will fit on any PVS14 objective lenses.  For L3 PVS-31A /  GPNVG-18; May also fit on Argus PVS-31A and APNVGSold as singles, if you need two buy two. These cannot be shipped to the USA.