Victorian white porcelain spare pot for a potty chair. The overall diameter at its widest is 11 1/2" and fits in about 9 1/2 opening.This gives you a lip of 1" all the way around. It tapers to 6 3/4" at the very outside bottom. In very good condition it only has what looks like the number 11 on the bottom. No other markings. No chips, cracks  or serious stains. Hard to find original potty chair, commode chair pot.