--- You wrote: Hi All, It's that time of year again, when I need to replace the oil wicks inside my Pfeiffer turbo pumps. This usually involves a whole lot of profanity and torn skin as I try to unscrew the locking cover. Has anyone figured out how to get these covers off without tremendous difficulty? Much obliged, Rick --- end of quote --- Which kind of cover to you have? A socket will work on one type. I use a screwdriver bit and a 1/4" wrench on the type with the slot. The third type I use an aluminum plate which has been fitted with screws that are the correct distance apart to fit in the holes in the cover.