Maxim Defense Industries Heavy Buffer, JP Silent Capture Spring, AR-15, Only Fits Maxim's CQB Stock, Black MXM-47571
Specifications:

Type	Capture Spring
Model	JP
Dimensions
Size
Material	Tungsten/Stainless Steel
Action
Trigger
Safety
Thread Pattern
Finish	Tungsten
Bolt Type
Hand
Hammer Type
Max Capacity