Mass a Units si kilogram, kg a cgs- gram, g USC-slug, slug Defined in terms of kilogram based on a specific cylinder kept at the international bureau of Weights and MeasuresMass ◼ Units ◼ SI – kilogram, kg ◼ cgs – gram, g ◼ USC – slug, slug ◼ Defined in terms of kilogram, based on a specific cylinder kept at the International Bureau of Weights and Measures