I assume it's just the plastic twist to lock bulholder, of late ford has been using soldered in bulbs, these are the exact same bulbs as the non soldered in ones, only the soldered ones have the wires on the capless wedge bulbs bent down and are then soldered with spot solder machine.
You can resolder some wedge bulbs in the holder, of another option is to get earlier bulb holders, exactly the same but they don't use the soldered in bulbs.
tabetha