It's made from 6061-T6 aluminium in the USA to ensure it's both incredibly strong and durable, with cutouts and contoured edges to reduce the weight. - 6061 T6 Aluminum - Made in the USA Sizes:1" 35mm - 40mm - 45mm - 50mm Colors: Black, Gold, Gun-Metal Description: The Split II Mini Stem is the scaled down 1" steer tube version of its ever so popular big brother.