The carrier has cut the price of its all-you-can-fly pass for summer travel in half after an earlier promotion spiked interest in the program. Effective immediately, the Go Wild pass will cost $499. The promotion runs through May 31.

Purchasers will receive unlimited flights (at one cent each) for five months between May and September. All domestic and international routes are included, including Puerto Rico, Mexico, and Latin America. Bag and assigned seat fees will still apply. Travelers will not earn frequent-flyer credits on their trips.

It’s a steep discount from the normal $999 rate, but it’s not the cheapest price that the pass has sold for this year. In February, Frontier offered the “MoviePass of the sky” option for just $399, which caught the attention of many would-be travelers.

Should you opt to enroll, there are a few things to know.

First, you’ll need to be flexible, as tickets only become available for booking the day before flight departure for domestic travel, and 10 days before flight departure for international travel. They’re also subject to blackout periods.

Additionally, the pass will auto-renew at the end of summer—and it won’t be at the discounted rate.

Frontier’s promotion of the pass comes as the travel industry braces for what could be the busiest summer in years. Expedia’s Summer Travel Forecast shows flight searches are up 25% compared to a year ago for the June–August period. And Delta Air Lines last month reported record advanced bookings for this coming summer.

Frontier’s all-you-can-fly sale follows a failed merger with Spirit Airlines last summer and a tumultuous six months for rival Southwest Airlines, which had a disastrous holiday season and last month halted all flights for a short period due to equipment issues.