COST-EFFECTIVE GOODS - Our 2028 series aluminum profile connector set contains all the required parts to complete the installation of 20mm aluminum extrusion at a 90 degree angle. Package includes 30pcs 2028 Corner Bracket, 60pcs M5 x 8mm T-Slot Sliding Nuts and Hex Screw Bolt, 1pc Wrench for set screw WIDE APPLICATION - The 2028 corner brackets is widely used building industrial aluminum frame structures, 3D printers, CNC routers, CNC laser cutters, CNC plasma cutters, 3D engraving machines, machine guards, robotics projects etc SUPER CRAFT - Our 2020 extrusion corner bracket set is made of high quality material well tested by the manufacturer to meet your daily needs. The T-Slot Aluminum Extrusion and M5 x 8mm Hardware Slide In T-Nuts are made from high quality carbon steel galvanized. Black stainless steel hexagonal screws, more rust resistant, no oil stains EASY INSTALLATION - If you like DIY industrial frame construction, don't hesitate to use our aluminum corner bracket to connect pieces of 20mm aluminum extrusion at a 90 degree angle suitable for most of metric 20 Series Aluminum Profile Extrusion and 2020 European Standard Aluminum Profiles Slot 6mm Colour:Black & Silver Material:aluminium Package Contents: 1 * Wrench 30 * 2028 Corner Bracket 60 * T-Slot Sliding Nuts 60 * M5 Hex Screw Bolt