Use on 25mm x 25mm Extrusion Profile, 1010 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 20mm aluminum extrusion at a 45 degree 135 degree angle suitable for most of metric 10 Series Aluminum Profile Extrusion.