Perfect for testing fragrance and essential oil scents. Use them to make your own blends or to get a more accurate smell of your other oils. Just dip the narrow end of the strip into the oil (or put 2-3 drops on it) and let it sit for a few seconds. You then hold the strip 3-5 inches from the nose and take a whiff. Use the wide end of the strip to write down the oil name or blend so you don't forget or lose your recipe! Measures 5 1/2 x 3/8 inches.