PetLock Max Flea & Tick Treatment for Medium Dogs offers a 4-month supply of protection against fleas and ticks. Designed for dogs weighing between 11-20 lbs, this treatment helps to rapidly kill fleas and may reduce the incidence of flea allergy dermatitis. PetLock Max kills existing fleas on dogs within 12 hours of application. This squeeze-on treatment is easy to apply and provides effective control against these pesky parasites. PetLock Ultra is specifically formulated for use on dogs and puppies over the age of 7 weeks. **Key Features:** * 4-month supply * For medium dogs 11-20 lbs * Kills fleas within 12 hours * Helps prevent flea allergy dermatitis * Easy to apply squeeze-on treatment * Suitable for dogs and puppies over 7 weeks old * Treatment and prevention of ticks and fleas. * Also effective against mosquitoes and biting flies.