Classic titanium cap. The most popular color is champagne gold. I wonder about aluminum caps. They're soft, so the threads strip easily and look unsightly. Balance is important, after all. Supreme style titanium, with its excellent metal and carefully applied coloring, is the best match for a knob made of beautiful precious wood. ★If you purchase this with a knob, we will offer it for 2200 yen, deducting the box fee and shipping. Please contact us before you pay for the knob.