Pfizer - Waterproof, Pour-on Insecticide. Contains an exclusive polymer that makes it waterproof. Longer-lasting than all other pour-on insecticides. Controls horn flies up to 11 weeks, face flies for at least 4 weeks. Also helps control biting lice, sucking lice, stable flies and horse flies. Water-based so it’s safe on cattle and environment. Safe on beef cattle, non-lactating and lactating dairy cattle, and calves. No withdrawal time for slaughter or milk. No offensive odor when applying. Easy to spot red plastic container.