KNS Precision FN FAL/ STG58 Duplex Crosshair Black. 240 aperture. Crosshair Size .010 Diameter. Crosshair Material Heat treated. Installation Replaces post sight w/o modifications to gun. Specifications for KNS Precision FN FAL/ STG58 Crosshair Iron Gun Sights: Manufacturer: KNS Precision Gun Model: FN FAL Color: Black Additional Features: Duplex Crosshair Rear Aperture Size: 0.24 in Country of Origin: USA Package Contents: KNS Precision FN FAL/ STG58 Crosshair Iron Gun Sights What firearm models does the manufacturer say KNS Precision FN FAL/ STG58 Crosshair Iron Gun Sights is compatible with? The manufacturer says that KNS Precision FN FAL/ STG58 Crosshair Iron Gun Sights is compatible with FN FALKNS Precision FALDU: FN FAL/ STG58 Duplex Crosshair Black