Thickness= 8mm side length= 1.97 inches heavy duty, 2020 aluminum extrusion bracket used for 2020 series aluminum profile slot 6mm(works well) 20pcs 2020 aluminum extrusion black corner(W=0.78in L=1.97in H=1.97in ), 40pcs M5 2020 t nuts, 40pcs M5 screws. You can contact with us by amazon if you have any questions for our products, we will give you a satisfactory solution within 24 hours