Can someone look under there transmission and help me??

[Rob 4092xx]

I have a 2009 H3.

I was underneath it today and noticed there are two holes on the underside of the transmission.

I know the larger hole (about 1 1/4" round) takes a thin aluminum plug that pushes in to cover it.

My question is this....does any type of plug go into the smaller hole (about 1/3" round) or is this one open all the time?

Thanks!!!!