bolts in floor behind rear seat??

[Mint68]

I just got the spare tire carrier for my blazer, the one that bolts to the floor behind the rear seat, and there is two small bolts in the floor between the carrier and the rear seat. They are small, 3/8 maybe, and only a couple inches apart. What are they for? The jack, or does the jack sit behind the drivers seat. If someone could tell me what they are for or post a picture of what goes there that would be great.