Feature：

➤ for GHK AR GBB series
➤ Drop-in replacement
➤ Increase of rate of fire to 18 rounds per second (may differ based on gas pressure and inner barrel length/weight of BB)
➤ For converting of AR15 to non-stock or folding-stock models
➤ Maintain bolt locking function of GBB
➤ Compatible with old and new versions of GHK M4 GBB

➤ For VFC AR GBB series
➤ Drop-in replacement
➤ Increase of rate of fire to 18 rounds per second (may differ based on gas pressure and inner barrel length/weight of BB)
➤ For converting of AR15 to non-stock or folding-stock models
➤ Maintain bolt locking function of GBB