Yes, I've got two under front wing strips on both the WC51 12 volt and Katy the ambulance 6 volt. You can't see them but when on at night show the real width of the vehicle. I had some spare 12 volt so tried them, as LED's really work on a maximum voltage, they work fine on the 6 volt. I haven't altered the 6 volt indicators, just to much hassle working out what resistors would be needed.