Abstract: A cleaner package for receiving materials a constituent or constituents of which are to be separated and/or cleaned includes means defining an inlet chamber and an outlet chamber which are axially spaced and have at least one centrifugal cleaner unit interposed therebetween. The opposite ends of the cleaner unit respectively define a first passage for inflow of said materials thereto and a second passage for outflow of a portion of said materials therefrom. The inflow passage has means defining an inlet exposed to said inlet chamber while the outflow passage is arranged to discharge to the outlet chamber. The initial portion of said inflow passage, including said inlet, is directed in a substantially straight line path, the sense of which is substantially the same as that of the central longitudinal axis of the cleaner. The construction provided enables an easy slip fit mount of the cleaner unit.