clamps are not clamps, they cannot be tightened. The angle bracket is made of heavy plastic with a stiff tension spring for easy handling.
Pros
MULTIPURPOSE AND WIDE USE - These corner brackets are very suitable for welding, drilling, furniture making, photo framing, woodworking, joining cabinet and furniture repairs, woodworking, etc. They are very suitable for very small wood projects such as photo framing , You can build beehives, closets and many boxes.