Die-cast from aluminum alloy to help dissipate heat, resist breaking, warping and cracking. Trailer hub cap Includes oil window, 1 standard vent plug & 1 ESP (Extended Service Plug), side pipe fill plug and gasket, mounting bolts not included. Bolt holes = 6, bolt circle = 6 3/4”, bolt hole size = 5/16”, fit = Trailer. Approximate dimensions = flange OD 7 1/2” flange ID 5 7/16” height 3 11/16”. Replaces: Stemco️#343-4195 SKF️#1696.