Kills and repels fleas and ticks for 8 continuous months in one easy-to-use, non-greasy, odorless collar. Quickly kills fleas within 24 hours of initial application. Reinfesting fleas are killed within 2 hours. Prevents tick infestations within 48 hours after application. Kills and repels reinfesting ticks in as quickly as 6 hours. The Seresto collar is water-resistant* and remains effective following a shampoo treatment, swimming or after exposure to rain or sunlight. *Seresto is water-resistant and remains effective following a shampoo treatment, swimming or after exposure to rain or sunlight. Under normal conditions, effectiveness lasts for 8 months. In order to maintain an eight-month duration, dogs must not be bathed more than once per month. For dogs that swim once a month or more, the control duration is reduced to 5 months for flea control and reduced to 7 months for tick control.