The IBM Industrial Space Saving Keyboard was a variant of the SSK designed for blending in with industrial environments - in particular, heavily within the automotive industry. In a familiar fashion to the relationship between the IBM Enhanced Keyboard and its industrial variants, the only difference is the grey casing designed to hide the dirt and discolouration expected to be inflicted upon the device within an industrial environment. Functionally, SSKs and industrial SSKs are identical. In particular, industrial SSKs seemed to have been popular in the automotive industry during the early '90s.