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 guarantees you to stay on zero. Features: Attaches to any 1913 picatinny rail Perfect (M4) co-witness height Stainless steel clamp Precision laser engraving