Flea Tick Collar ProGuard Plus - Large Dog (safe pet protection from pest bites infestations larvae lice mosquitoes) BEST VALUE  NO OTHER PEST CONTROL PRODUCT IS MORE EFFECTIVE for the price. Drops are great products but expensive. Pills are also great products but more expensive. All of these products use the same chemicals. EFFECTIVE  MOST effective form of pest control available for dogs and cats. Fleas, ticks, and other pests always migrate upward. The collar is worn around the neck of your pet and will stop all pests before they reach the head. The entire body is protected but concentrations around the neck will be highest. SAFE  Pest control chemicals, which are similar in all pest control products, are safe for use. These chemicals, being present in many products can exceed safe levels if combined with the same chemicals in other products. IE: If you use drops then don't also use the collar. OTHER USES  If you do use pest control drops then you may also use the collar for short durations when you expect higher than usual contact with pests such as a visit to the woods or a farm. Collars can also be placed into vacumm cleaners to kill pests as you vacumm them up.