JMac Customs Skeletonized Tube for Ultra Compact M4 Stocks Black. (With proper folding adapter) The ST-5 was designed specifically to allow stocks such as the LWRC Ultra Compact Stock to collapse all the way up to the folding mechanism for a shorter overall length and profile. The ST-5 is the perfect option for compact stocks and braces Fits most M4 style stocks/braces Lightweight and Rigid Attaching a stock to a pistol makes it an SBR and requires NFA approval. You are responsible for knowing and following your local/state/federal laws JMac Customs LLC is not responsible for the end users misuse of our products. Specifications for JMac Customs ST-5 Skeletonized Tube for Ultra Compact M4 Stocks: Manufacturer: JMac Customs Color: Black Features of JMac Customs ST-5 Skeletonized Tube for Ultra Compact M4 Stocks Integrated QD Sling Sockers 5" Length 5 positions Compatible with SIG folding mechanisms 7075 T6 Aluminum Type III Hardcoat Anodized Requires a mount or folding mech to install Package Contents: JMac Customs ST-5 Skeletonized Tube for Ultra Compact M4 Stocks JMac Customs ST-5: ST-5 Skeletonized Tube for Ultra Compact M4 Stocks Black