• Not for use with standard AR10/AR15 buffer tubes
• Works with Maxim CQB Stocks/Braces
• Standard steel weights

JP's Silent captured Spring for Maxim stocks will get rid of the annoying ringing that you get with a standard AR spring. This spring is setup for standard rifles that are not exceptionally over-gased. We recommend the heavy version of this product if you are going to put it into an SBR or suppressed rifle.