That is a Maxi-Mini, the largest of the S. tapetum. They get to about 6-7 inches. There is a intermediate S. tapetum that get to about 1.5 inches and the tinu S. tapetum that only get to about .5 inches.
IMO, these are different species of mini carpets. I have no idea why they get group to the same species, other than they have not get too closely study