Each refill lasts up to 50 days and can be replaced with any Air Wick Freshmatic refill. Simply remove the old fragrance can and insert the new one into the unit with the nozzle facing outward until you hear a click. To remove fragrance, unplug unit and firmly pull the can down. About Air Wick Developed in 1943, Air Wick was one of the first odor eliminators and left homes smelling clean and fresh. Today, Air Wick products are available in a variety of formats and fragrances, from robust automatic sprays to indulgent candles, so you can ensure your home always smells fresh and inviting and creates just the right atmosphere to enhance your mood.