These keys are commonly used to lock and unlock RV hood compartment doors and RV baggage compartment doors. The Southco keys also fit most Jayco pop-up camper storage trunks located on the front tongue area of the camper trailer.
Each key has 4 notches inside the barrel. The old part number is E3-26-715-15, and the current part number is Southco E3-5-15. Some older keys may have a different head style.