Looking for rock solid stability and dead-on accuracy in a fixed sight? Troy Industries Fixed BattleSights get the job done. This permanent, rail-mounted alternative to a standard A2 sight allows limitless mounting options on all-length rails with a serrated ramp to eliminate glare. Provides a continuous zero, unflinching durability and peace of mind. Features: Sight can be moved or taken off without permanent modification to the firearm. Snag-free apertures at factory height. Sight is designed to work on same-plane rail systems only. Will not work with a railed gas block that is higher or lower than the receiver. Front sight must be mounted at the same height plane as the rear sight. Railed gas blocks that are lower than the receiver height will not zero properly.