This glass pillar holder flips to hold 3" diameter pillar candle or 4" ball candle on one side, and a 4" diameter pillar on the other side.
Another nice idea: add a straight-side glass votive cup into the cavity on the 4" side - as shown in the photo. Add a few accents to the rim of the candle holder and you have an instant centerpiece! (try glass beads or marbles.)