Posted 25 Sep 2017 StormWerkz threaded plug for .22 AR's, Sig556 pistols, SB brace adapters, etc. Lets you add the StormWerkz folding mechanisms to any receiver with 1-3/16-16 threads. NOT for standard AR-15's rifles. $28 For more information please go to www.stormwerkz.com AR Thread Receiver Block Duluth, Minnesota, United States Share this post Link to post Share on other sites