5.3 exhaust manifold o-ring?

[b-mac]

Hey guys,

I need help identifying my exhaust manifold gasket o-ring. Not a donut.

This is the o-ring that goes at the bottom of the exhaust manifold before the exhaust pipe.

The engine is a 5.3 from 2004 Buick Rainer AWD.

I thought I had it found, but the one I purchased is too large.

Guy at the local GM parts counter said the one I have was used on all 5.3s from 99-on.

See pics. I appreciate the help guys.