The product ships in an easy-to-grip plastic bottle fitted with a roller-ball applicator that allows controlled, mess-free placement of the liquid. The formula combines pyrethrins with the synergist piperonyl butoxide along with di-n-propyl isocinchomeronate and n-octyl bicycloheptene dicarboximide to repel and kill flies on contact. It is labeled for use on horses, ponies and dogs and is meant to be applied around the nose, eyes, ears and mouth, as well as around wounds and other surface lesions, rather than directly onto them. Before each use the bottle should be shaken well, the cap removed, and the roller applied lightly to the treatment area before the cap is replaced. Hands should be washed with soap and water after handling the product. Horses and ponies should not be treated more than once per day, while dogs can be retreated after about a week.