Think socket is 30mm 12 point. The 12 point bit if fairly obvious from the photograph but many sockets this size are 6 point so it's an easy mistake to order the wrong one.
Thanks very much Spike, you are correct, it is 30mm 12 points, just found one, I was using the wrong multi point head socket, that I use for the oil filter top, far too thicker wall to go in the hole,
Have a nice day.
Ami