The Power Plate Backer offers thicker, stronger aluminum in an innovative shape that provides increased stud rigidity, while reducing track wear and tear. 1.250" wide x .145" thick aluminum for greater strength and support. 5/16" hole size. Innovative shape - Stud Boy added a radial lobe to a standard 1.125" backer reducing wear and tear on the track and increasing stud rigidity. By reducing the weak flat corner area of the square backer they have reduced unnecessary weight and bending of the corners. Use the Power Plate and receive the best benefits of both square and round backer plates in one design.