Cylence Ultra Insecticide Cattle Ear Tags are for effective control of buffalo fly, including control of organophosphate resistant fly populations on beef and dairy cattle. Cylence Ultra is impregnated with Betacyfluthrin, a synthetic pyrethroid insecticide along with Piperonyl butoxide, which acts as a synergist. The insecticides are slowly released from the tag to protect cattle against buffalo fly for up to 4 months. Cylence Ultra dual tag system spreads the active and protects both flanks.