FELIWAY Classic 30 Day Cat Calming Odourless Refill for Pheromone Diffuser, 48ml - Helps Solve Common Signs of Stress in Cats & Kittens, Veterinary Recommended, Drug-free, Clinically Proven1 FELIWAY Classic REFILL: The FELIWAY Classic refill pack contains 1 x 48ml refill, compatible with a FELIWAY Classic diffuser. REDUCES SIGNS OF CAT STRESS: FELIWAY Classic helps cats feel calm, and reduces signs of stress such as scratching, urine spraying, scratching, fears, tension, and conflict. Each diffuser covers large living spaces (up to 70m). PROVIDES 4 WEEKS OF CALMING SUPPORT: FELIWAY Classic plug in diffuser uses the science of pheromones