rubber o-ring on drain plug question

When I pulled the oil tank drain plug, what looked like the remains of a rubber o-ring fell into the strainer. I pulled the 2 sump drain plugs and didn't see anything like that.

Can someone tell me if there is only an o-ring for the oil tank drain plug and not the 2 sump drains?

Does anybody know the size of the o-ring that gets replaced... I'll pick it up at the local auto parts store instead of driving 40 miles to the Stealer.

Any help is appreciated!

Much appreciated!!! Thanks for the info.