Specifications: Size: EU20-M5 Materials: Carbon Steel Surface Treatment: Nickel Plating Type (Optional): EU20 1.Nuts are made of high quality carbon steel. Nickel-plated surface for good resistance to rust and oxidation 2.Kit consists of 50pcs nuts, your choice of thread: EU20-M5 conforms to European standard 3.Easy to use and convenient for connecting aluminum profiles with other parts 4.Suitable for aluminum extrusion profiles after European standard: EU20 is used for profiles with a 6 mm slot,