Bonus Pack - 2 refills. Each refill has 2 scents. Automatically alternates throughout the day so you don't get used to the same scent. Eliminates odors in the air caused by bacteria. Freshness you notice for more than 30 days (on low). Important Safety Instructions Please Save: For use with Febreze NOTICEables Alternating Scented Oil Warmer. For use with P&G Air Freshener SY-982. Made in USA.