Abstract: Disclosed herein is a level comprising a horizontal component comprising a first terminal end and a second terminal end; a first vertical component comprising an end joined to the first terminal end of the horizontal component, wherein the first vertical component is attachable to a first vertical side of a jamb; and a second vertical component comprising an end joined to the second terminal end of the horizontal component, wherein the second vertical component is attachable to a second vertical side of a jamb; wherein the level squares, levels, and plumbs the jamb. Further disclosed herein is an assembly comprising two levels disposed on a jamb such that the sides of the jamb are held rigid and secure, and the angles of the jamb are held at a constant angle to increase the ease of installation of the jamb.