The Adaptil Calming Collar is a discrete collar that steadily releases appeasing pheromones to calm your dog down and ease them into new and stressful situations such as house training a puppy, travelling, as well as during trips to the vet or kennels. In puppies the collar helps your new canine companion to settle into the family by releasing comforting pheromones that would naturally be released by their mother to calm and reassure them, helping to minimise night crying and loud barking, whilst helping them to learn more quickly and better socialise with other dogs. Read more… When in snug contact with the dog’s skin, the dog’s body temperature warms the collar and encourages the diffusion of pheromones into the local environment. As a result, it is vital the Adaptil collar is in close contact with the dog’s skin at all times. Three collara are available: for puppies & small dogs (neck circumference up to 37. 5cm) and for medium to large dogs (neck circumference up to 62. 5cm). Each collar lasts 4 weeks and can be replaced as often as necessary. Adjust to fit comfortably and trim any excess if necessary, and check the collar at regular intervals as it must remain snugly against the dog's neck. This can be worn and used alongside our Adaptil diffuser or Adaptil spray, depending on what best suits your dog's needs.