●Packed: 20pcs L joints brackets + 40pcs set screws + 1 wrench for set screw,more convenient than L-Shape only. ●Material: Electrophoresis Zinc alloy, has excellent features in high abrasion resistance, rust proof and stability. ●Advantage:Concealed corner brace, the L corner bracket can be completely hidden in the slot of the aluminum extrusions. ●Suitable for 2020 european standard aluminum profiles slot 6mm And other suitable size profiles. ●Used for building industrial aluminum frame structures, 3D printers, CNC routers, laser engravers, robotics projects.