Celica Forums General Discussion Engine and Performance Exhaust Header Donut Size?

Anybody know what size donut for a 2004 celica gts with a 2zzge engine?
Been trying to find one but no luck. Recently replaced my header too and using the old donut on it.
Here's the link of new donut that I bought - OBX Exhaust Header [ebay.com]
I asked the seller but he doesn't sell it.