Make of durability copper, these nut resist rust and exposure, ensuring longevity in humid or harsh environments like lab equipment and outdoor maintenance These copper nut feature excellent thermal conductivity for quick heat fusions bonding, ideal for industrial applications requiring high strength fastening without deformation under high temperatures Copper construction, providing safe usage for healths households, especially in children ' s toy or furniture assembly Designed for easy insertion without additional tools, saving time during assembly or repairs, making it ideal for quick part replacements in maintenance work The 420pcs set includes M3M4M5 sizes to accommodate various project needs, eliminating separate purchases for different nut sizes, perfect for DIYers and professional, Manufacturer: Tsophreniq