The 4in x 5in L-Bar is actually made out of two 4.5in pieces of aluminum tubing. One of them is mitered and welded into the other, giving a full height of just over 5in. Because the weld takes up room on the other tube, we round it out and call it about 4in long. Instead of offering up a "4.72in x 4.5in (But Also There's A Weld) L-Bar," we shortened the name to lessen the mouthful, saving you time to mount your accessories and ride while the weather's still nice.
Clamp not included.