Kill ticks. Detach ticks. Prevent diseases that come from ticks. With a time-controlled delivery system, the Preventic Tick Collar spreads the active ingredient from head to tail using your pet's skin and coat oils. The result? 3 months of protection against ticks. For dogs over 12 weeks of age, over 60 lbs and necks up to 25". Not for cats. Active ingredient: 9% Amitraz.