This is a Magpul Industries Stock known as the UBR Gen 2, model MAG482-ODG.
The UBR GEN2 is an adjustable stock for AR15/M4 and AR10/SR25 platforms" designed to offer similar strength and stability as a fixed stock with a consistent and comfortable cheek weld in any position. An update of the revolutionary Utility/Battle Rifle (UBR) stock" the UBR GEN2 features a fixed cheek piece to provide a consistent cheek weld in any of its eight positions" and is compatible with Carbine as well as A5 and SR-25 length buffer systems. Designed to accommodate large bore AR calibers and withstand severe impacts" the UBR GEN2 is nearly five ounces lighter while retaining all the durability its predecessor was legendary for. Comes standard with front and rear QD sling attachment points" two footman's loops" the ergonomic MOE SL(TM) angled-toe rubber butt-pad" and customizable storage compartment. Made in U.S.A.
Features:
Mounts on a durable custom Receiver Extension tube (included)
Accommodates carbine buffers and springs
Enhanced lock mechanism
8 total positions