Had mine fitted earlier today. I think its 2.25" with a tanabe back box and it sounds amazing. On idle its so much deeper and sounds lush but the best part is when you get on full boost it starts screaming, quite high pitched - sounds like a vtech lol. Came to £105.75 including VAT. They put a hefty brace in that connects it to the same bracket that the standard exhaust connects to - so hopefully the mani shouldn't crack at all.
Next step is to completely heat wrap, but I friggin' love it!
VIDES!