The Adams Plus Flea & Tick Collar for Dogs is perfect for medium to large size dogs. It provides quick relief from biting fleas and ticks and continuous protection for up to 7 months. Our collar prevents infestation by killing 3 stages of the flea and tick lifecycles. This collar provides one-step to treatment and prevents reinfestations. Even when wet or completely submerged, the collar continues to be effective. This collar is fully adjustable and water-resistant.Tetrachlorvinphos 14.55%, (S)-Methoprene 1.02%, Other 84.43%."