The supplied photo can be a bit miss leading.
The reality is there is only one metal straight edge. But.. there is no real reason to complain. The 45 degree angle is bang on, the try square setting:
is exactly 90 degrees, the straight edge is imperial on one side and metric on the other. I was just building a project and used this lay-out tool over and over.
When I am fitting hardware, hinges, hasps etc. I use a square and a depth gauge so that I can fit things accurately usually I turn to this tool as my depth gauge.
When I am taking a tool box to a work site, (kids house) I take my KREG Multi-Mark Lay-Out Tool. I like its versatility it is four tools but I only have to carry one up the stairs from the shop.
A funny little aside, from thetoolstore.ca
This could become the most popular tool in your shop, according to the grand kids.