ARK Design 48mm lug nuts are manufactured from billet 7075 aluminum (referred to as "Duraluminum" in Japan) and then hard anodized for addiitonal anti-wear and anti-corrosion properties. Lug nuts are close ended to retain a clean and stylish look on the street or track. Available in M12 x 1.25 and M12 x 1.50 threads.