Flumethrin 2.25% w/w; Propoxur 10% w/w. Bayer Kiltix Dog Collar Large is a high-quality collar smeared with chemicals like Flumethrin and Propoxur which safeguards the dog against ticks and fleas for up to 7 months. Dogs are highly vulnerable to ticks and fleas during the rainy season and the infestation of the external parasites can be a cause of many allergies and infections. It works on principle called the hotfoot effect where fleas and ticks are repelled before they can infest on dogs.