If your firearm doesn't already have a 1913 attachment rail on the rear choose the appropriate adapter! Skeleton Stock 8-inch with JMAC's 1913 folding mech - not assembled) 2x Integrated QD Sling Socket 8" Length Drilled and tapped for optional cheek risers - will be available in the future Compatible with SIG folding mechanisms 7075 T6 Aluminum Hard-Coat Anodized Only 5.36oz without folding Mech JMAC 1913 Folding Mechanism Mfg: Jmac Customs