RECMAR’s "L" beam Sets have prepunched installation holes on 8” centers and are completely assembled with carriers and end stops (no cords to break). Curtain pin hooks insert into rings of the nylon wheel carriers, which roll friction free along the track. Use prebent rods for valance over “L” Beam Assemblies. “L” Beams are made from high quality mill finished 6063-T5 aluminum.