VET APPROVED, WATERPROOF BIO FORMULA - 6 month of strong protection: New German Technology gives you effective flea and tick preventic for dogs and Puppy for 6 month! COST-EFFECTIVE PEST DEFENSE - collars use advanced technology to refine essential plant oils into a PVC carrier to reduce chemical irritation. Still, they are not suitable for pets that are sick or have skin allergies. NO MESS TREATMENT AND CONTROL - effective against Fleas - larvae, lice, Ticks and Mosquitoes. This flea product for dogs was designed to be HELPFUL either for small medium size or extra large pets. SUITABLE FOR ALL SIZES - the rolf club collar in pack is easy adjustable, maximum length 26.5 inches. Provide veterinarian level of care at an affordable and fair price.