Plastic Potty to Porcelain Throne?

Thanks, DF! Exactly the kind I've been looking at, but what is under that carpeted box under the plastic commode?

I guess my post was vague, but I don't need more height, I just want to do away with the short plastic thing and have a porcelain/china thing and the carpeted box would make the new one too tall. :(

I could just rip out the box and find out for myself, but I was hoping someone could tell me what to expect before doing so.