<E30> oil pressure sender size?

[bolhuijo@xxxxxxxxxxxx]

 Can someone tell me how big a socket is required to remove the oil
pressure sending unit from my M20/B25?  I'm guessing 22mm, but I don't
want to run out and buy a socket that I won't ever need... 
 ...can't get any sort of wrench on that darn thing.

TIA

- --
  John Bolhuis    | These are no ordinary monkeys --
 bolhuijo         | these are mean, spiteful, butt-biting
  @domain.elided   | monkeys with an obvious mission: conquest.
                                        -tabloid.net

------------------------------