AR-15/M-16 XTI Xpress Threat Interdiction Sight Set - Standard Tritium F/S, Tritium Stripe Rear Sight. New Production in Unopened Factory Package. $130 Shipped XS Sight Systems AR-15/M-16 Xpress Threat Interdiction tritium replacement sights are quite possible the finest AR sights made for fast sight acquisition in any lighting condition. The XTI Sight Set is designed for quick acquisition in CQB situations and makes a great secondary sight system for competition guns. These sights are angled and offset making them an excellent addition to a 3-Gun rifle when using magnified optics as the primary sight. The lightweight design does not add bulk or significant weight to the rifle and the sights are reversible for left hand shooters. The front sight is easily rotated to adjust for elevation and the rear sight can easily be loosened using the supplied Allen Wrench to adjust for windage. By simply "Dotting the I" you can be assured that you are on target quickly without having to perform extra unnecessary sight alignment during a critical moment. XS Sight upgrades are all precision machined from stress-proof steel. 24/7 Tritium Stripe rear sight. Standard Dot Tritium Front Sight: Standard Dot for general use out to intermediate ranges.