The piece of VENT HOSE not the plastic fitting. The fitting comes with a new battery- take the existing vent hose in to home depot and match the hose size/diameter/thickness and cut off a longer piece.

 

Not sure if you read it all but i got my battery at the wreckers without the connector. .. vent hose is easy.. i thought maybe you got the fitting somewhere else ..

Its okay ill just measure it up and start looking
Thanks anyway .