The diffuser helps you nurture your relationship with your cat/s, by creating a loving environment for them and reducing undesirable behavior related to stress. The diffuser releases a substance of vegetal origin which helps to calm cats in a natural way. Just screw the vial onto the diffuser unit and plug it into an electric socket. Then leave the diffuser switched on continuously to keep your cat relaxed and friendly. Each diffuser refill lasts about 4 weeks. It covers an area of 50mq.