This high tensile steel knocker is made by precision CNC machines. It fits all Glock series GBB pistol (include Glock 19) of T.Marui. It is an enhancement item, which is specially made for professional shooter and competition needs, because:

1) High precision dimension increases shooting reliability and sensitivities;

2) High tensile steel strengths construction, increases durability and reliability;

3) Smooth surface finishing is used to reduce friction inside your GBB Glock and improve smoothness knocking movement;

4) Dimension is modified for increasing efficiency and reducing risk of misfire. Therefore, it has difference dimension from the original T.Marui knocker.