This is a Magpul Industries Stock known as the MOE SL-K Carbine Stock, model MAG626-ODG.
A drop-in replacement buttstock for AR15/M4 mil-spec carbine buffer tubes" the SL-K is designed for compact PDW style weapons or users desiring a small and light stock. Features a short and slim profile" a smaller rubber butt-pad with rolled toe for easy shouldering and sure grip" and a 1.25" footman's loop with the ability to accept an optional M-LOK QD Sling Mount for push-button style QD sling swivels. A new" unique" ambidextrous release latch minimizes rattle on the receiver extension without requiring additional locks" levers" or springs*. Made in U.S.A.
Features:
Sloping cheek weld combines a slim profile with user comfort
Dual-side release latch
Rollover on the toe allows for better fit when using body armor