Oil burners are clear glass pipes varying in size from 3.5 inches to 4 inches in length and are made of solid glass. These oil burners feature a glass stem with a rounded end that has a hole at the top that allows for airflow. To use, simply fill the rounded end with your favorite essential oils and place it over a flame to release the fragrance into the room. This glass is very easy to clean by rinsing with water and drying. Make sure you replace your oils after each use. These products are for home fragrance oil use only.