Technical Drain plug key size please:)

[stuartwhite]

I desperately need to change the oil and check the levels in the gearbox, but the drain plug key wasn't with my Tipo when i received it :bang:

can anyone please tell me the Allen Key size so i can get a new one?

(Its a '89 if that makes any difference)

 

[multipete]

12 mm allen key. gear box level plug is at front next to reverse light switch,and oil should come out when plug is removed for gear box level.