Cheek piece will add an additional 1″ height on cheek rest. Easy to add the Butt Plate Assembly or 3-Axis Butt Plate Assembly: The assemblies will add an additional 1 1/16″ length of pull with extended length buttplate. Interchangeable with standard A2 or A1 buttstocks or any aftermarket buttstock with overall length of approximately 10.5″. *NOT interchangeable with carbine/collapsable rifles with telescoping assemblies (6-position tubes)