Works, although not very accurately. Also, my ruler was bent when it arrived, probably due to shipping. I think the $13 Irwin is the best option and I returned that one. However, the ruler was also bent on the Irwin as it was shipped in a box containing a heavy item. Be careful when buying cheap gauges like this one. If the item comes from the factory without a box, it will likely bend during shipping. The thing works as it should, if not very precisely. If you just want a simple combo squareβ¦