This is a complete set of four used headlight bulbs, marked with the FoMoCo logo. These sets come with two high beam and two low beam bulbs. Each bulb is tested by the electrical department. If you're trying to keep your Cougar or Mustang as close to original as possible, you should definitely grab a set.
These bulbs are date coded, so if you want a particular date, be sure to mention it in the comments section of your order.