Calming collar for Cats with pheromone technology (like feliway)
SENTRY® Calming Collar for Cats | Sentry
Comfort Zone 2 Pack Cat Calming Pheromone Collar for Cats | De-Stress Your Cat | Helps Cats Feel Safe, Happy, and Calm While Reducing Unwanted Behaviors,White : Amazon.co.uk: Pet Supplies
Calming Collar for Cats, Adjustable Anti-Anxiety Pheromone Cat Calming Collars, Breakaway Waterproof Natural Long Lasting Calming Effect Stress Relief Pet Collars for Small Medium and Large Cats : Amazon.co.uk: Pet Supplies