SIG SAUER MCX/MPX TRAX Locking Folding Rifle Stock Black. 0. Improving on our wildly popular original thin folding stock this new version is a must-have for your rifle. Lighter and stronger than before this refined version maintains the skeletonized profile while adding key performance upgrades. It now includes an integrated steel-reinforced limited-rotation Sling QD (Quick Disconnect) slot and a removable polymer cheek piece with increased height over bore for improved sight alignment with optics. Finished with a newly contoured lightweight buttpad for added comfort and control. Compatible ONLY with MCX and MPX or rifles with 1913 stock interface and will not work with the SIG SAUER CROSS. Specifications for SIG SAUER MCX/MPX TRAX Locking Folding Rifle Stock: Manufacturer: SIG SAUER Gun Type: Rifle Gun Make: SIG Sauer Gun Model: Sig Sauer MCX-SPEAR LT SIG Sauer MCX SIG Sauer MPX Color: Black Length: 10 in Weight: 12 oz Stock/Brace Material: Steel Polymer Package Contents: SIG SAUER MCX/MPX TRAX Locking Folding Rifle Stock What firearm models does the manufacturer say SIG SAUER MCX/MPX TRAX Locking Folding Rifle Stock is compatible with? The manufacturer says that SIG SAUER MCX/MPX TRAX Locking Folding Rifle Stock is compatible with SIG Sauer MPX SIG Sauer MCX Sig Sauer MCX-SPEAR LTSIG SAUER 8901908: MCX/MPX TRAX Locking Folding Rifle Stock Black