This VKARSTK Ncstar Blastar Mil-Spec AR15 thumb hole stock is fixed and has a internal storage compartment in pistol grip and rubber butt pad for comfort. Stock is designed to fit MIL-SPEC AR15/M4 carbine buffer tube only. Stock is constructed of polymer and hard anodized aluminum. AR stock features multiple QD sling cup points to install a QD sling (cups not included). Comes with black Thumbhole Stock and mounting bolts and tool included.