I have the IWB that fits my 5". It fits my 4" as well with no problems. Not all that comfortable. There are no supporting tabs, i.e. comptac, that spread the weight around. It is essentially a storm holster with one less thickness of the kydex. The belt loop fits over your pants and is secured by the belt.
If i had to do it again, i would get the C-tac holster.