NOTE: Quantity is per tube. You must select a quantity of 2 for DUAL TUBE Systems. The package includes only the focusing aperture, not the night vision device. Please verify the quantity when placing your order.FEATURES: The focusing aperture is an advanced night vision goggle (NVG) accessory designed to enhance visual clarity at various distances. It features a smooth-action, high-performance optical iris that can be quickly adjusted to control the amount of ambient light entering the NVG. Allows users to view objects clearly at all distances without manually adjusting the focus on night vision goggles. Offers infinitely variable iris control from fully open to fully closed, optimizing light input while maintaining auto-focus functionality. Equipped with a replaceable, high-quality Corning glass sacrificial lens that protects the NVG objective lens from dust, debris, and impact. The lens can be replaced quickly without tools. Enables rapid adaptation to changing light conditions via an easy-to-use adjustment ring that opens or closes the iris. Designed for secure and straightforward attachment to compatible night vision devices. Compatible models: TYPE 1 VARIANT (NAVAIR) 37mm OD: AN/PVS-6 AN/PVS-7 AN/PVS-7B/D ANVIS-9 AN/PVS-14 NEPVS-14 AN/PVS-23 (F5050YG) DTNVG DTNVS RNVG TNVC-BNVG-M (Artemis) MOD3 TYPE 2 VARIANT (GROUND) 34mm OD: AN/PVS-15 AN/PVS-18 AN/PVS-31A BNVD MUM-14 GPNVG