Water intake plug replacement

Hi,

Despite best efforts, I managed to drop the water intake plug that is on deck into the sea..

I've been searching the forum for the specifications but can't find them. (for a Swan 47)

Does anybody known the size and type of thread for that plug?

Peter

Missing plug

I saw the same product on a Hallberg Rassy (including the "vatten" imprint) -- maybe worth checking with them.

Best,

Martin