I find it somewhat unbelievable in this day and age of the NEC that you are actually able to use the 15A GFI on a 20A circuit. Seems like they want everything bigger and stronger but they still allow a 15 amp rated plug on a 20 amp branch circuit. Nice to know we can save ourselves a little money on supplies from time to time when everything else's price is skyrocketing (ahem..copper,conduit,etc..).