A vehicle trailer hitch including an aluminum tubular U-shaped strut and a cast aluminum receiver mounted thereto. The processes can comprise leaching the aluminum-bearing material with an acid so as to obtain a leachate comprising at least one aluminum ion, at least one iron ion, at least one rare earth element, and a solid, and separating the leachate from the solid. The retaining ring contains a through channel, whose cross-sectional surface has a form which substantially corresponds to the cross-sectional surface that is delimited by the inner wall or outer wall. The stacking bus connects the first repeater and the second repeater and is configured to relay status signals between the first and said second repeaters. The sizes DP and gaps GAP of the dummy pattern elements composing the dummy pattern are respectively same in X-direction and Y-direction. It comprises a substantially rectangular bottom case 11 having a battery accommodation portion 18 for accommodating secondary batteries 13 and a top case 12 to be assembled with the bottom case 11 for closing the battery accommodation portion 18.