This steel Hi-Capa knocker is made by precision CNC machines. It only fits original T.Marui Hi-Capa series GBB pistol. It does not fit any '1911 GBB pistol using single stack magazine'. It is an enhancement item, which is specially made for professional shooter and competition needs, because:

• - High precision dimension increases shooting reliability;
• - Dimension is modified for increasing sensitivity and reducing risk of misfire. Therefore, it has difference dimension from the original T.Marui sear;
• - High tensile steel strengths construction, increases durability and reliability;
• - Smooth surface finishing is used to reduce friction inside your pistol and improve smoothness of mechanical movement.