The Adams Plus Flea and Tick Collar for Dogs is perfect for small or large dogs. It provides quick relief from biting fleas and ticks and continuous protection for up to 7 months. Our collar prevents infestation by killing all 3 stages of the flea and tick lifecycle. This collar provides one-step treatment and prevents reinfestations. Even when wet or completely submerged, the collar continues to be effective. This collar is also fully adjustable, and the outer shield reflects direct light up to 450 feet.