Seresto is an 8-month preventative produced by Bayer. The collar reduces the risk of them transmitting disease such as ehrlichiosis, Lyme disease, Rocky Mountain spotted fever, and anaplasmosis. This collar not only repels ecto-parasites like fleas and ticks, but it kills them when they bite your pet! It is odorless, not greasy, and designed with a safety-closure mechanism. In the unlikely event of your pet being trapped, the animal’s own strength is sufficient to widen the collar to allow for quick release.