(S)keletonized(T)ube(5)inches long and 5 positions 

This M4 tube adapter replaces the standard buffer tube to ensure the stock folds as flat as possible! (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

• Integrated QD Sling Sockers
• 5" Length
• 5 positions 
• Compatible with SIG folding mechanisms
• 7075 T6 Aluminum
• Type III Hardcoat Anodized

FM-SM-1913 - 1913 Folding Mechanism

• Clamps on any "1913" or "Picatiny" Rail
• Works with all of our ArmBar, Skeleton Stocks and Skeleton Tubes
• Works with SIG MPX/MCX folding braces/stocks
• Folds Left or Right
• Has 2 height adjustments
• 4140 HT
• Black Nitdride    
• Torque spec: 20 in/lb.
• Adds approx .5" to stock/brace length
• Allows your stock/brace to lock in the folded position

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.