Centering Gauge

I'm sorry I don't know the official name of this tool...therefore I'm calling it a centering gauge. (If someone can let me know the official name, I could update this thing.)

I'm new to using my small lathe and I saw a video of someone using a gauge like this to quickly find the center of his log.

I whipped up a quick design in Inkscape. I then laser cut/engraved this centering gauge on my K40 out of acrylic.

Hopefully someone else can find it useful as well!