This is a ProMag Stock, model AAM1022.
The Archangel Nomad Conversion Stock for the Ruger 10/22 with a 25 round magazine installs easily and this folding stock features a drop in fit that requires no gunsmithing. Proprietary carbon fiber reinforced polymer construction will ensure a lifetime of hard use. Features a folding buttstock with recoil pad folds from 36-3/4" to 28-3/8" overall length with standard 18 1/2 barrel" aluminum reinforced full length picatinny top rail" sights - Adjustable for windage and elevation" hand guard accessory rail" extended magazine and enhanced bolt release" aluminum flash hider and hand stop with integrated sling mount" dummy suppressor (fits 18 1/2 standard barrels)" 2 storage compartments and comes with the new AA922-A1" .22 LR (25) RD magazine.
Features:
AAM1022 Easily installed on your Ruger 10/22
Ultra light stock weighs only 3 lbs.
Comes with the new AA922-A1 .22 LR (25) RD magazine