A lens-interchangeable camera system includes: an interchangeable lens unit storing lens characteristic data corresponding to parameters of lenses in a discrete manner; and a camera body unit to which the lens characteristic data is transmitted from the interchangeable lens unit when the interchangeable lens unit is mounted. More particularly, the catalysts are for vapor-phase hydrogenation of methyl esters to fatty alcohols under fixed-bed conditions, where conditions are typically in a temperature range of 200 to 250\xb0 C. The example system comprises a key phrase field for accepting a search term, a data table and a search unit. The connector housing is formed so as to be releasably connectable to a bushing unit.