Shop › FAB DEF AR15/M4 BUTTSTOCK BLK FAB DEF AR15/M4 BUTTSTOCK BLK $52.99 F.A.B. Defense L-Core, AR-15 Buttstock, Fits Mil-Spec And Commercial Tubes, Black FX-GLCOREB Quantity: Add To Cart Added! F.A.B. Defense L-Core, AR-15 Buttstock, Fits Mil-Spec And Commercial Tubes, Black FX-GLCOREB