last week i was doing some work on a buddy's ca mp5 and i broke the barrel retainer clip on the hop up, i want to ask tirador to order one (a bunch

) for me but my friend does not have the diagram, if you have the diagram can you tell me the part number of this little clip! (the hop up is not the marui one it's the one that is adjustabe by the ejector)
any help would be greatly appreciated i did some googleing but found nothing!
thanks in advance!