This natural backflow incense cone can burn for as long as 30 minutes, but the air-purifying effects don’t end when it stops burning. For hours later, your space will have a refreshing, crisp smell and feel. These are sandalwood fragrance large hollow incense cones, ideal for creating the perfect aroma for your space. Be rest assured that they are made from a combo of natural and pure ingredients and are totally free of synthetic materials. This means that they bring the original scent of nature into your home, guaranteeing a feeling and sense of completeness and wholesomeness.