This metal 90 degree bracket measures 3 x 3 x .25 x 2.81 inches with eight .328 inch diameter thru holes on 1.5 inch centerlines. Perfect for your 80/20 t slot aluminum extrusion project! 8020 corner bracket is compatible with 15 Series aluminum extrusions or 1.5 inch based extruded profiles. Works with many of our competitors aluminum extruded frame. Strong durable brackets that can be easily removable and reused. Top line quality control with smooth de-burred edges, tight tolerances, and a anodize finish ensures a perfect bracket. Made out of 6063-T6 aluminum, this can be used as brackets for shelves, home improvement projects, t slot aluminum extrusion, or 3D Printer applications. #3320 assembly hardware is recommended (but not included) for 8020 1.5" based applications. The 8 hole - inside corner bracket is an external fastening method that creates a 90 degree connection and has four holes on each side of the bracket, comprised of two rows and two columns. It requires no machining services and can provide infinite positioning along the profile T-slot, allowing a large degree of adjustability. The 8 hole - inside corner bracket engages the 2-degree drop-lock feature when the assembly bolts are tightened to the required torque. It is a fastening method that can be repositioned and reused.