Are you looking for sights that can take serious punishment and keep you on-target? Samson manual folding sights are the most robust combat sights on the market. Accepts all aftermarket front sight post replacements with Mil-spec dimensions. All sights lock in the deployed position. It is not intended for lower height gas block rails. The durable construction and solid mounting system guarantee you to stay on zero. FEATURES: Material: 6061-T6 aluminum Finish: Type III class 2 hard coat anodizing Attaches to any 1913 Picatinny rail Perfect (M4) co-witness height Stainless steel clamp Precision laser engraving Manual Folding Rear Sight (A2): Mfg: Samson Manufacturing Corp