Advecta Ultra Flea Tick XL Dogs 4 Month Supply Waterproof Topical Fast ActingAdvecta Ultra Flea & Tick Protection for Dogs uses the same active ingredients as K9 Advantix. Starts working through contact to kill and repel fleas, ticks, and mosquitoes within 12 hours with no prescription needed. Waterproof, fast acting topical drops provide 30 day protection at an affordable price. 4 month supply for XL dogs. Key Features: 4 month supply for small dogs Kills fleas, ticks & mosquitoes in 12 hours Same active ingredients as K9