As the images show, I like using this nifty tool for those long pieces of wood.
It came with no manual. I want to use it's other capabilities.
A search for "t square bubble" and I found this.
https://wenproducts.com/products/12-inch-aluminum-combination-square-with-bubble-level
What other uses can I use it for?
That's called a combination square set.
The metal rule is the base for the other parts.
The part on the left in the first photo allows you to find or set an angle between it and the rule.
The top part on the second photo sets a 45 or 90 degree angle to the rule.
The bottom part is used to put the rule across the center of a square or circular object, allowing you to, by drawing two perpendicular lines, to find the center.
