MAX 40 is a new sustained release, insecticide ear tag containing a highly concentrated, maximum dose of Diazinon insecticide making up 40% of its volume by weight. MAX 40 has been designed to control the rate at which the active (Diazinon) is distributed throughout the surface of the animal. This unique controlled release formulation extends the effectiveness of the tag. The sustained release rate along with the tag's high potency increases the number of weeks animals benefit from control of the targeted pests up to 20 weeks.