Merck Double Barrel VP Insecticide Cattle Ear Tags provide quick knockdown and control of both horn flies and face flies. They combine two different active ingredients, an organo-phosphate and synthetic pyrethroid, to minimize resistance development-eliminates the need for ear tag rotation. 6.8% Lambdacyhalothrin and 14% Pirimiphos Methyl. Ear-tag fly control is approved for use on beef cattle, non-lactating dairy cattle and calves of all ages. Unique triangular shape prevents tag from breaking off at neck. Treats 10 head of cattle. For up to 5 months control of horn flies and face flies, use two tags per head on beef and non-lactating dairy cattle and calves.Note: This product may require up to 2 additional days for order processing prior to shipping