[Phantom 335i]

So I picked up a performance exhause for my E92 335, and it didn't come with the 2 clamps to attach it to the stock exhaust. I am thinking of picking up some clamps tonight and putting it on but my question is what size are the clamps I require? I think I saw 2.5" somewhere but don't remember

Thanks

Edit: For anyone needing the clamp size info the ones from BMW are 60mm