Square 90 Degree Positioning Squares, 4 Inch Carpenter Squares for Woodworking, Clamping Squares Angles Clamps Tool Carpenter's Square for Picture Frames Squares Assemble Cabinets Drawers (4 Pack)

I use these in my wood shop when glueing up stuff that should be at 90 degrees. I have found them surprisingly useful and have used them more than I expected to. They are a good size for small projects - I would want something bigger if you're working on bookshelves or big furniture.If you do woodworking, you really do need these.

These small 90 degree clamping squares have a very small error over four inches so should not be relied upon for trying to square sides several times larger. They are helpful (for me) to hold work pieces in rough alignment until other methods can be used to bring things into square.I may get some more as they are very sturdy and fit into small spaces.

For small frames they are fine. My frame was 14 X 47 inches and that was about the limit for these small clamping squares. I probably should have bought larger ones.

These things are perfect. Perfect 90 and great for clamping to things to ensure you get a perfect 90. Yes there are metal ones out there and they are nice but they are also a lot more expensive. These will do the trick.

Love the convenience of the smaller size for small projects. Very sturdy and manageable. Only disadvantage is also its advantage, the size. The size works great for small projects but is a restriction for larger projects. I would still give it an A+. I used them to make some small laptop desks for my daughter due to the home schooling during this pandemic.