Inside-Corner Bracket Gray Unfinished Number of Mounting Holes 2 Overall Height 18 mm Single Nut Overall Length 18 mm Overall Width 18 mm Fastener Thread Length 8 mm Aluminum Fastener Thread Size M4 Inside Corner Bracket Style Open Includes Fasteners Yes 20 Series System of Measurement Metric Connection Angle For Slot Width 5 17/64 mm Includes (2) Hammer Nuts (2) Screws