300tdi aux belt

Hi thinking of buying a spare aux drive belt to keep in the back of the disco. Not sure which 1 to get as there are different part numbers??
To fit 1997 300tdi will be getting a DAYCO belt but just need to make sure i get the right 1, anyone know the part number for the right belt??

Cheers

Check your VIN, they run upto and from a certain number...

Both 7 rib multivee but one is an inch longer IIRC