· FRONTLINE Shield provides proven flea and tick protection with repellency action against ticks and mosquitoes· Kills and repels all stages of ticks, including those that may transmit Lyme disease· Kills chewing lice and adult fleas, flea eggs and larvae to prevent re-infestations· Convenient to use, easy to apply, waterproof formula protects for a full 30 days· For dogs big and small; effective for puppies as young as 9 weeks and weighing at least 5 pounds