NAVAL AIR STATION MEDAL PARKING OR ENTRY PASS WINGS

I am not exactly sure what the wing is for either for parking or authorization to enter the base. The wings are made of medal with a old silver frosting the size is 10" wide by 2 3/4" high and about 3/4" thick. There are the initials NAS and number 228 stamped on a shield and that has a fouled anchor in the background. I do not know the period of it but defiantly not recent. There are two holes for fastening. Condition good +