FELIWAY Friends is a convenient, easy to use solution for reducing cat conflict in households with more than one cat. FELIWAY Friends contains a copy of the Cat Appeasing Pheromone which is clinically proven to help cats live in harmony and alleviate signs of conflict like tensions, fighting, blocking, staring, chasing, hissing and swiping. The FELIWAY Friends refill should only be used with the FELIWAY Friends diffuser device. Simply screw the refill vial into the diffuser unit, plug the diffuser unit into an electrical socket, switch on and leave on continuously for 4 weeks. Each refill vial provides constant support for 4 weeks. Replace after 4 weeks for continued benefits.