Aluminum alloy casting, class 3m or 10m, cond.T6 spec.Qq-a-601, 13.250 in.0/a lg.1.250 in.W, 2 arch, 5.312 in.C to c arch, 1.562 in.Between base and in.Side of arch, 4 mounting holes equally spaced on center 0.281 in.Dia.2 end slots 1.000 in.Lg.By 0.312 in.Wide