The Magpul UBR GEN2 is a rock-solid adjustable stock for AR-15/M4 and AR-10/SR25 rifles that mimics the strength and cheek weld of a fixed stock while retaining collapsibility. A constant cheek-weld design keeps the comb height identical at every length-of-pull setting, the storage compartment holds a spare battery or CR123, and the reinforced build stands up to hard use with a suppressor or optic. Black.