Use on 1 Inch x1 Inch Extrusion Profile, 10 Series Aluminum Profile Connector Set widely used for building industrial aluminum frame structures, 3D printers, CNC Routers, CNC laser cutters, Robotics Projects. Aluminum Corner Bracket used to connect pieces of 25 mm aluminum extrusion at a 90 degree angle suitable for most of metric 10 Series Aluminum Profile Extrusion.