Offset rail ends are a cup-shaped fitting used with a brace band, carriage bolt and nut to connect the top rail or brace to a post. Carriage bolt and nut sold separately. These have 1 hole and the tab is fastened to top of cup at a 45º. Combination rail ends are a cup-shaped fitting used with a brace band, carriage bolt and nut to connect the top rail to a post in conjunction with connecting the truss rod. Carriage bolt & nut is sold separately. These have 2 holes for 3/8" truss rods and 45º tab having 1 hole. Brace rail ends are a cup-shaped fitting used with a brace band, carriage bolt and nut to connect the top rail or brace to a post in conjunction with connecting the truss rod. Carriage bolts and nuts sold separately. Tab has 2 holes and is welded to cup parallel to the ground, there are no holes in the cup. Please see additional information below for further details