FIPROtec Combo spot-on solution for dogs contains Fipronil and the insect growth regulator S-methoprene. These ingredients not only kill adult fleas, ticks and biting lice but also impedes on the flea life cycle. This results in the prevention of any exposed eggs and/or larvae from developing in your home for up to 8 weeks. Key Features & BenefitsKills adult fleas for up to 8 weeks. Kills ticks for up to 4 weeks. Effective against fleas, ticks and biting lice. Prevents eggs laid by exposed fleas from developing for up to 8 weeks. Which Treatment Will I Need?Spot On for Small Dogs: Suitable for dogs over 8 weeks of age and weighing 2-10kgSpot On for Medium Dogs: Suitable for dogs over 8 weeks of age and weighing 10-20kgSpot On for Large Dogs: Suitable for dogs over 8 weeks of age and weighing 20-40kgHow to Apply1. Hold the pipette in an upright position, twist and pull the cap off. 2. Turn the cap around and place the other end of the cap back on the pipette. 3. Push and twist the cap to break the seal, then remove the cap from the pipette. 4. Part the coat on the back of the animal at the base of the neck in front of the shoulder blades until the skin is visible. 5. Place the tip of the pipette onto the skin and squeeze the pipette several times to empty its contents completely and directly onto the skin in one spot.