Go to www.thetford.com click parts and look at the aqua -magic aurora it MAY be the same but an updated model it lists part number located by using the exploded view.
Alternative is to click on 'find a dealer'.
You could get more help in the right section being a thetford permanent toilet is it in a caravan,motorhome or boat.
Mind you some people have been known to use them while doing up a house. What better way to be sitting on one and deciding which wall to pull down or the type of tiles you want in the kitchen.
Nobby
April 2008