Here are some pics of it hanging out and helping a couple of candles. There probably isn't a great need for words here since the tools are very easy to use. BTW, this was part of the Egg Hunt loot. 

Pictures:

1. The cast of characters. Regular 8 oz. JJ, tabbed wick with a stick'em, small crafty clothespins, small Wick Centering Tools, and 8" Handy Wick Tube.

2. The wick on the right is a little slouchy, and needs a little pin to keep it straight. Also, three sizes of the device.

3. Another view of the two candles.

4. Centered wicks.

Misc. thoughts:
Although I usually end up with decently centered wicks before using this tool, using them has made the process more efficient with less thinking involved... especially on the days when I have felt like I just stepped off of the stupid bus.

At first glance, it seems to be a very simply made device. But upon further inspection, a fair amount of thought was given on it's specifications. I've mainly been experimenting with the small one. It fits very easily on the JJ. The short downward (end) parts look to be slightly tapering in so that it rests comfortably on top while giving the slightest bit of a hug to the jar threads.

Conjuring up candles has become more efficient (around here) with these impressive little tools.