This fits our 27x27mm round or heart shaped diffuser lockets. Clay round or heart shape is made from dead sea terra cotta clays from Israel. 8 replacement clay disks that fits 27×27 locket. One simply puts a couple drops of essential oil onto the clay diffuser inside the metal locket and it will soak up and hold that scent. The diffuser can be hung around the house, placed in a drawer, hung in a car, carried in a purse or even worn around the neck. When it starts to become less potent, simply put a couple more drops on it. ♥´¨) ¸.•´ ¸.•*´¨)¸.•*¨) (¸.•´ (¸.•`♥~. One of a Kind Enjoy item!!!.