Can anyone tell me what this type of cover is called? I have found a few name for it myself whilst trying to remove and re-install it but none of them a suitable for public use. I really want to know primarily because I want to find a tool to remove and replace it. I refuse to accept that a professional bike mechanic would use a slippery adjustable spanner or start hitting it with a hammer. I would like to be able to service the bottom bracket as needed without damaging anything. Sorry if this is an obvious question, but again I come to you after a long a fruitless Internet search. Thank you.