The Slatkin & Co Home Fragrance oils The Perfect Christmas Tree Refill Bulbs are a festive addition to any home during the holiday season. These refill bulbs are specifically designed for adults who want to add a warm and inviting scent to their living space. The Christmas & Holiday scent is perfect for creating a cozy atmosphere, making it the ideal choice for the holiday season. With the oil form of these fragrance oils, they can easily be used in a variety of ways such as in a diffuser or on a cotton ball to freshen up any room.