Lethal® Human Scent Eliminator Field Spray & Activator, created by chemists and field tested by professionals, contains the latest in human scent elimination technology. Lethal® Field Spray & Activator has a separate concentrated activator that charges the product with odor eliminating bonding agents. A permanent binding effect takes place. This is not always the case with other scent eliminators. Also because you activate this product yourself you know that you are getting the freshest product possible. This product lasts 90 days after activation.