Good on Southwest one round trip or two one way trips. You can use this voucher for a round trip, two one-way vouchers, or even by two people on the same flight. There is no systemwide blackout dates but this Award has seat restrictions. So please plan ahead when making your flight reservations as certain holiday or peak travel periods will be in high demand and your desired flight may not be available for Award travel. Cost includes the $10 - 9/11 tax that I will pay for you when I reserve your flight. After that, you can change the destination, date, or time of travel at no charge any time prior to flight.

More information: http://www.southwest.com/rapid_rewards/use_ticketless_award.html