PYthon II MagnuM insecticide cattle ear tags are synergized pyrethroid tags containing Zetacypermethrin plus piperonyl butoxide. Approved for use on beef and dairy cattle, including calves and lactating dairy cows. Use 1 tag to control most strains of horn flies for up to 4 months and pyrethroid-susceptible strains of horn flies up to 5 months. Aids in the control of face flies, stable flies and house flies up to 4 months. Controls biting lice and aids in the control of sucking lice for up to 3 months. Use the Y-Tex UltraTagger to apply. Ear damage may result if used in calves less than 3 months of age. | Y-Tex PYthon II Magnum Ear Tag 20 Count