Y-Tex Python Insecticide Cattle Ear Tags Combo Black is designed to protect calves, beef and dairy cattle against insect pests. It contains Zetacypermethrin and Piperonyl Butoxide which effectively controls biting flies, face flies, horn flies, spinose ear ticks, Gulf Coast ticks, as well as aid in controlling black flies, house flies, small horse flies, sucking lice and stable flies. It is also safe to use on lactating cows. These tags can be applied using the Ultra Tagger Plus Applicator. Each box comes with 20 black tags.