Aluminum alloy, grey enamel finish, 2.975 in. O/a lg, 0.691 in. Thk, 2.530 in. W, 4 mtg holes 0.334in. Ida, mtg holes unthd, 1.750 in. C to c of holes along the length, 1.620 in. C to c of holes along the width, 1.125 in. Diameter of recess, 0.562 in. Radius of recess