Seresto 81857944 Adjustable Small Dog Flea & Tick CollarKills 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. Highlights: For 8 month protection against fleas & ticks for puppies 7 weeks of age & older & dogs weighing up to 18 lb Starts to repel & kill fleas within 24 hours of initial application & re infesting fleas within 2 hours Repels & kills ticks within 48 hours of initial application & re