A toroidal transformer enclosure is disclosed. The cleaning unit is configured to rotate in response to an activation of the rotation member. The five-position thumb button can be used to shift the key assignments of the finger buttons and thus greatly enlarge the size of the response set. The released hydrogen from the ZVM-PCS can be applied to anaerobic bioremediation. The arms may be spaced transversely of each other and do not overly each other in plan view, so enabling all arms to be formed by depositing a single layer of arm forming material. The oil reservoir is made so as to communicate with the ventilation path.