Troy Industries SSIG45SMDBT 45 Degree Folding BattleSights set for AR-15/M4/M16. Folding 45 degree sights fold compactly to both sides of the rifle. Ambidextrous sight base, compatible with magnified optics. Sights sit at factory height. Stainless steel cross-locking mechanism keeps the sight upright and zeroed under extreme conditions. Note: Designed for same-plane rail systems only; will not work with railed gas blocks higher or lower than the receiver.