AFAIK it uses a 6pt 5/8 = 16mm, if this plug has a longer insulator it may need a longer socket. There are sockets with finger inserts like OE (Hazet) or magnetic, a rubber insert in a socket is not the best thing to use on plugs installed deep in a hole.Is that the one that uses a 12 point socket? Do they make a 12-point spark plug socket with a rubber grommet?