This 20-piece set of hanging car freshener bottles is designed for refillable fragrance use. Each bottle has a capacity of approximately 8 ml and is made of clear glass with a wooden cap, an inner stopper, and a hanging string. The set provides a sufficient quantity for replacing different fragrances or for using in multiple locations. The bottles measure about 1.1 inches (2.8 cm) in diameter and 1.9 inches (4.8 cm) in height, with a folded hanging rope length of about 7.87 inches (20 cm). To use, fill the bottle with essential oil or perfume, shake gently so the wooden cap absorbs the fragrance, and then insert the bottle stopper. The wooden cap is intended to release the scent gradually. The bottles can be hung in a car, office, bedroom, bathroom, wardrobe, or other small space. Because the bottles are empty, fragrance liquid is not included. The clear glass makes it easy to check the liquid level. This set is a practical choice for people who want a larger supply of refillable hanging diffusers and who prefer a simple, transparent design.