Our professional quality 12 piece fire cupping jar set is made of medical grade molded glass with smooth, soft edges for the ultimate client comfort. Each cup has a flat top for safely resting cups after cleaning. Each cup is made of thick, heavy walled glass and is designed for use by traditional Chinese fire cupping techniques. Heat or fire from a candle, disposable lighter, or burning cotton/alcohol ball held inside the cup and then removed is customarily used to create the vacuum. Includes 12 Cups that are Finger Imprinted for easy gripping and extra accidental safety. - 4 cups of Medium (Lip Diameter: 2.24") - 4 cups of Large (Lip Diameter: 2.48 in") - 4 cups of Extra Large (Lip Diameter: 2.70") Complete Set of 12 Fire Cupping Glass Cups.