Buy your Maxim Defense JP Captured Spring System from BattleHawk Armory today! Maxim Defense is offering a JP silent Captured Spring System that is manufactured exclusively for Maxim Defense. This unit is designed specifically to be compatible with Maxim Defense CQB stock systems. The JP Silent Captured Spring System requires an open channel in your bolt carrier group assembly for the guide rod to pass during operation. Features- Maxim Defense MXM-47570 JP Silent Captured Spring Standard Buffer Tungsten/Stainless Steel Natural Finish