This herbal collar has been impregnated with natural oils extracted from selected herbs whose repellent properties have been known for centuries. The herbal essences are progressively release from the collar onto the dog's coat thereby discouraging fleas from inhabiting the dog. Containing no insecticides, this collar is non-toxic and has a pleasant aroma. Will last for approximately 3 months. Not recommended for puppies below 2 months of age.